snapraid/doc/snapraid_log.1

.TH "SnapRAID Log Format" 1
.SH NAME
snapraid_log \- SnapRAID Log Format
.SH DESCRIPTION 
This document describes the structured log tags output by SnapRAID,
which are designed to be used by tools monitoring the SnapRAID
processing state. The tags provide information in an easy\-to\-parse
format, ideal for automation and integration.
.PP
To capture these structured log tags, you must use the \`\-\-log\` option
with SnapRAID.
.PP
You can direct the output to a specific file, or force the output to
the standard output or standard error using the special arguments
\`>&1\` or \`>&2\`. Note that these arguments often need to be quoted on
the command line to prevent the shell from interpreting them.
.PP
Example:
.PP
.RS 4
snapraid status \-\-log \[dq]>&2\[dq]
.PD 0
.PD
.RE
.PP
The output tags strictly adhere to the following format:
.PP
NAME:VALUE:VALUE:VALUE...<EOL>
.PD 0
.PD
.TP
.B NAME
This is the primary tag identifier, always a lowercase string
without spaces (e.g., \`summary\`, \`block\`, \`info_time\`).
.TP
.B VALUE
Following the \`NAME\`, these can be additional sub\-identifiers,
descriptive names (like a disk name), or numeric/string data
values. They are separated by a colon \`:\`.
.TP
.B <EOL>
Each tag is terminated by an end\-of\-line character.
.PP
This document provides a summary of the tags generated by SnapRAID.
For the most detailed and up\-to\-date information regarding the meaning
and context of the values, it is recommended to check the source
code\'s \`log_tag()\` statements.
.PP
When a path is output, it is always escaped using a backslash (\\) as
the escape character.
.PP
The following characters are escaped into sequences:
.RS 4
.PD 0
.HP 4
.I The colon
is escaped to \\d.
.HP 4
.I The newline
is escaped to \\n.
.HP 4
.I The carriage return
is escaped to \\r.
.HP 4
.I The backslash
is escaped to \\\\.
.PD
.RE
.PP
Some tags are output only when the \`\-\-gui\` or \`\-\-gui\-verbose\` option
is used. They provide extra verbose state and runtime progress only
useful for a GUI interface.
.PP
Integer values are marked as \`uint\` when they are unsigned and as \`int\`
when they are signed. However, for practical purposes you can treat
all of them as signed integers.
All integer values should be assumed to be 64 bits wide, regardless
of the signed/unsigned marker.
Floating point values are marked as \`float\`.
.SH CONFIGURATION TAGS 
These tags report the memory usage and global configuration.
.TP
.B conf:file:<path>
Configuration file loaded (escaped).
.TP
.B conf:missing:
Operating without a configuration file.
.TP
.B blocksize:<bytes>
The configured block size in bytes (uint).
.TP
.B data:<disk_name>:<dir>:<uuid>
The data disks as defined in the configuration file.
.RS 4
.PD 0
.HP 4
.I <disk_name>
The assigned name of the disk.
.HP 4
.I <dir>
The directory entry point of the disk.
.HP 4
.I <uuid>
The UUID of the filesystem containing the dir.
.PD
.RE
.TP
.B mode:<raidname>
The RAID mode used. One of \`par1\`, \`par2\`, \`par3\`, \`par4\`,
\`par5\`, \`par6\` or \`parz\`. The number indicates the maximum
number of simultaneous disk failures the array can withstand.
.TP
.B <parity_level>[/<split_index>]:<path>:<uuid>
The parity files as defined in the configuration file.
.RS 4
.PD 0
.HP 4
.I <parity_level>[/<split_index>]
One of \`parity\`, \`2\-parity\`,
..., \`6\-parity\`. This corresponds to the level of redundancy.
In case of split parity, the parity name is followed
by \`/N\` to indicate the split index, where N starts
from 0. The \`/0\` is always omitted.
.HP 4
.I <path>
The path (escaped).
.HP 4
.I <uuid>
The UUID of the filesystem containing the path.
.PD
.RE
.TP
.B pool:<dir>
The configured dir to the pool mount point (escaped).
This is the optional mount point for the \'pool\' feature.
.TP
.B share:<dir>
The configured dir to the pool mount point (escaped).
This is the optional mount point for the \'share\' feature.
.TP
.B autosave:<bytes>
If the autosave feature is enabled, and after how many bytes
(uint). This specifies the interval for content file saving.
.TP
.B filter:<pattern>
All the active filters with their patterns. These patterns
exclude specific files or directories from the SnapRAID array.
.TP
.B filter:nohidden:
If the no\-hidden filter is enabled, meaning hidden files/directories
(starting with \'.\') are excluded from the array.
.SH CONTENT TAGS 
These tags report the information stored in the content file.
.TP
.B content:<path>
The absolute path to a content file being used (escaped).
Content files store the metadata (like file hashes and timestamps)
for the array.
.TP
.B content_write:<path>
The absolute path to a content file being written (escaped).
You will see multiple writes as the content file is saved in
multiple copies.
.TP
.B content_parity:<parity_level>[/<split_index>]:<uuid>:<path>:<size>
The parity files as stored in the content file.
.RS 4
.PD 0
.HP 4
.I <parity_level>[/<split_index>]
One of \`parity\`, \`2\-parity\`,
..., \`6\-parity\`. This corresponds to the level of redundancy.
In case of split parity, the parity name is followed
by \`/N\` to indicate the split index, where N starts
from 0. The \`/0\` is always omitted.
.HP 4
.I <uuid>
The UUID of the disk containing the path as stored
in the content file.
.HP 4
.I <path>
The path (escaped).
.HP 4
.I <size>
The size of the parity file (uint).
.PD
.RE
.TP
.B content_data:<disk_name>:<uuid>
The data disk as stored in the content file.
.RS 4
.PD 0
.HP 4
.I <disk_name>
Name of the data disk.
.HP 4
.I <uuid>
The UUID of the disk filesystem as stored in the
content file.
.PD
.RE
.TP
.B content_allocation:<disk_name>:<size>:<free_size>
The size of disk and parity as stored in the content file.
.RS 4
.PD 0
.HP 4
.I <disk_name>
Name of the data or parity disk.
.HP 4
.I <size>
The size of the data in the disk or parity (uint).
.HP 4
.I <free_size>
The free size in the disk or parity (uint).
.PD
.RE
.TP
.B content_info:<kind>:<counter>
The counters in the content file.
.RS 4
.PD 0
.HP 4
.I <kind>
One of file, hardlink, symlink, dir_empty,
block_bad, block_rehash, block.
.HP 4
.I <counter>
The number of elements (uint)
.PD
.RE
.SH DIAGNOSTICS TAGS 
.TP
.B version:<version>
The version of SnapRAID run.
.TP
.B unixtime:<time>
The current time in the unix format (uint), representing
seconds since the epoch.
.TP
.B time:<YYYY\-MM\-DD HH:MM:SS>
The current time in human format.
.TP
.B command:<command>
The command run. One of \`sync\`, \`scrub\`, \`check\`, \`fix\`, \`status\`, ...
.TP
.B argv:<number>:<argument>
All the arguments of the executable command. The 0 one is the
executable run.
.TP
.B memory:used:<bytes>
The total memory currently used by the application in bytes (uint).
.TP
.B memory:block:<bytes>
Size of the internal \`snapraid_block\` structure in bytes (uint).
.TP
.B memory:extent:<bytes>
Size of the internal \`snapraid_extent\` structure in bytes (uint).
.TP
.B memory:file:<bytes>
Size of the internal \`snapraid_file\` structure in bytes (uint).
.TP
.B memory:link:<bytes>
Size of the internal \`snapraid_link\` structure in bytes (uint).
.TP
.B memory:dir:<bytes>
Size of the internal \`snapraid_dir\` structure in bytes (uint).
.SH SCAN TAGS 
These tags report detected differences between the filesystem and the
content file. They are output for every discovered change.
.TP
.B scan:equal:<disk_name>:<path>
A file, link, or directory is equal (unchanged).
No action is required for this item.
Only produced when \`\-\-gui\-verbose\` option is used.
.RS 4
.PD 0
.HP 4
.I <disk_name>
Name of the data disk.
.HP 4
.I <path>
Path to the file/link relative to the disk mount
(escaped).
.PD
.RE
.TP
.B scan:add:<disk_name>:<path>
A new file or link was found that is not in the content file.
This item will be added to the array in a \`sync\`.
.TP
.B scan:remove:<disk_name>:<path>
A file or link has been removed from the filesystem
since the last sync.
.TP
.B scan:update:<disk_name>:<path>
A file or link has been updated (size, timestamp, or link target changed).
This item will have its content data blocks re\-hashed in a \`sync\`.
.TP
.B scan:move:<disk_name>:<old_path>:<new_path>
A file was moved on the same disk. This is an efficient operation
that only updates the path metadata without re\-hashing blocks.
.RS 4
.PD 0
.HP 4
.I <old_path>
The old path to the file (escaped).
.HP 4
.I <new_path>
The new path to the file (escaped).
.PD
.RE
.TP
.B scan:copy:<disk_name>:<path>:<source_disk>:<source_path>
A new file was found to be a copy of a file from another disk.
This is detected by matching file size and timestamp, and is an
efficient operation that avoids re\-hashing all blocks.
.RS 4
.PD 0
.HP 4
.I <source_disk>
The original file\'s disk.
.HP 4
.I <source_path>
The original file\'s location (escaped).
.PD
.RE
.TP
.B scan:restore:<disk_name>:<path>
A file\'s inode has changed but not its date\-time and size,
which suggests the file may be restored from backup.
The file won\'t be re\-hashed in \`sync\` as its precomputed hash
is assumed to be correct.
.PP
These tags provide a final count of all detected changes.
.TP
.B summary:equal:<count>
Total number of files and links whose metadata and data match
the current parity (uint).
.TP
.B summary:added:<count>
Total number of brand new files and links not present in the
last sync (uint).
.TP
.B summary:removed:<count>
Total number of files and links that existed in the last sync
but are now missing (uint).
.TP
.B summary:updated:<count>
Total number of existing files where the timestamp or size has
changed (uint).
.TP
.B summary:moved:<count>
Total number of files relocated to a new path or renamed but
retaining the same inode (uint).
.TP
.B summary:copied:<count>
Total number of new files created by copying an existing
protected file to a new path (uint).
.TP
.B summary:restored:<count>
Total number of new files matching a parity entry by
name/time/size but with a new inode (uint).
.TP
.B summary:exit:<status>
Logs the overall exit status of the command. The \`status\` is
one of the following:
.RS 4
.PD 0
.HP 4
.I equal
Indicates that no differences were found.
The array is already synchronized.
.HP 4
.I diff
Indicates that differences were found.
The array needs a \`sync\` operation.
.PD
.RE
.SH GENERAL PROGRESS AND EXECUTION TAGS 
These tags are used to report the runtime processing of the commands
\`sync\`, \`scrub\`, \`check\` and \`fix\`.
Only produced when \`\-\-gui\` option is used.
.TP
.B run:begin:<blockbegin>:<blockend>:<count>
A tag indicating the start of the command execution.
.RS 4
.PD 0
.HP 4
.I <blockbegin>
Starting block index (uint).
.HP 4
.I <blockend>
Ending block index + 1 (uint).
.HP 4
.I <count>
Number of blocks to process. It may be less
than <blockend> \- <blockbegin> + 1 if some blocks
are going to be skipped (uint).
.PD
.RE
.TP
.B run:end
A zero\-argument tag indicating the end of the command execution.
.TP
.B run:pos:<blockidx>:<blockdone>:<sizedone>:<perc>:<eta>:<speed_mbs>:<cpu>:<elapsed>
Detailed progress information during command execution.
.RS 4
.PD 0
.HP 4
.I <blockidx>
Current block index position processed (uint).
.HP 4
.I <blockdone>
Number of blocks processed (uint).
.HP 4
.I <sizedone>
Current size processed (uint).
.HP 4
.I <perc>
Completion percentage (uint).
.HP 4
.I <eta>
Estimated time to completion in seconds (uint).
.HP 4
.I <speed_mbs>
Data processing speed in MB/s (uint).
.HP 4
.I <cpu>
CPU usage percentage (uint).
.HP 4
.I <elapsed>
Elapsed time in seconds (uint).
.PD
.RE
.TP
.B sigint:<blockidx>:<msg>
A user interruption (e.g., Ctrl+C) was signaled. The process
is gracefully aborting.
.RS 4
.PD 0
.HP 4
.I <blockidx>
Current block index position (uint).
.HP 4
.I <msg>
Text message exactly as it\'s printed on screen.
.PD
.RE
.TP
.B msg:<level>:<msg>
Messages printed to the screen.
.RS 4
.PD 0
.HP 4
.I <level>
One of \`fatal\`, \`error\`, \`expected\`, \`status\`,
\`progress\` or \`verbose\`.
.HP 4
.I fatal
A fatal error occurred. Program will abort after this
message.
.HP 4
.I error
A generic error condition that doesn\'t prevent the
program to continue.
.HP 4
.I expected
An expected error condition. At present it
happens only when using the \`\-m\` option with files
expected missing.
.HP 4
.I status
A status message, usually providing context or a summary.
.HP 4
.I progress
A progress message, often part of an ongoing operation.
.HP 4
.I verbose
A verbose informative message, only shown in verbose mode.
.HP 4
.I <msg>
Text message exactly as it\'s printed on screen.
.PD
.RE
.SH THERMAL TAGS 
The following tags are produced by the thermal monitoring functions
when SnapRAID is processing, typically during operations that involve
disk access.
.TP
.B thermal:ambient:device:<hwmon_dir>:<name>:<temp_file>:<label>:<temp>
Logs a temperature reading found in the system using the Linux
/sys/class/hwmon interface. Only present in Linux.
.RS 4
.PD 0
.HP 4
.I <hwmon_dir>
The hwmon directory name (e.g., hwmon0).
.HP 4
.I <name>
The name of the hwmon device (e.g., k10temp).
.HP 4
.I <temp_file>
The temperature file name (e.g., temp1_input).
.HP 4
.I <label>
The label associated with the temperature sensor (e.g., Tdie).
.HP 4
.I <temp>
The temperature reading in degrees Celsius.
.PD
.RE
.TP
.B thermal:ambient:candidate:<temp>
Reports a temperature reading that is a candidate for the
ambient temperature, used in the heating model calculation.
.RS 4
.PD 0
.HP 4
.I <temp>
The candidate temperature in degrees Celsius.
.PD
.RE
.TP
.B thermal:system:candidate:<temp>
Logs a temperature reading from a connected disk that is being
considered as a candidate for determining the ambient system
temperature.
.RS 4
.PD 0
.HP 4
.I <temp>
The current temperature read from the disk
(uint, degrees Celsius).
.PD
.RE
.TP
.B thermal:system:final:<temp>
Logs the final ambient system temperature calculated. This
value is the lowest valid temperature observed among all
candidates, representing the room temperature.
.RS 4
.PD 0
.HP 4
.I <temp>
The calculated ambient temperature in degrees Celsius.
.PD
.RE
.TP
.B thermal:current:<disk_name>[/<split_index>]:<device>:<temp>
Logs the most recent temperature reading for a specific disk
device.
.RS 4
.PD 0
.HP 4
.I <disk_name>[/<split_index>]
The configured name of the disk.
In case of split parity, the parity name is followed
by \`/N\` to indicate the split index, where N starts
from 0. The \`/0\` is always omitted.
.HP 4
.I <device>
The unique device ID (uint).
.HP 4
.I <temp>
The current temperature read from the disk in degrees
Celsius.
.PD
.RE
.TP
.B thermal:highest:<temp>
Logs the highest temperature observed among all monitored disks
in the current measurement cycle. This is used for thermal
throttling.
.RS 4
.PD 0
.HP 4
.I <temp>
The highest temperature observed in degrees Celsius.
.PD
.RE
.TP
.B thermal:heat:<disk_name>[/<split_index>]:<device>:<count>:<data_points>
Logs the entire history of temperature data points collected
so far for a specific disk, used for fitting the heating model.
Only monotone increasing temperatures are included in the history.
.RS 4
.PD 0
.HP 4
.I <device>
The unique device ID (uint).
.HP 4
.I <count>
The total number of collected data points (uint).
.HP 4
.I <data_points>
A comma\-separated list of temperature/time pairs.
Each pair is formatted as <temp>/<time_offset>.
.HP 4
.I <temp>
Temperature reading in degrees Celsius.
.HP 4
.I <time_offset>
Time offset from the start of the thermal
monitoring (uint, seconds).
.PD
.RE
.TP
.B thermal:params:<disk_name>[/<split_index>]:<device>:<k_heat>:<t_ambient>:<t_steady>:<rmse>:<r_squared>:<max_error>
Logs the estimated parameters for the exponential heating model
(fit using least squares) and associated quality metrics for a
specific disk.
The model is: T(t) = T_steady \- (T_steady \- T_0) e^(\-kt),
where T_0 is the initial temperature.
.RS 4
.PD 0
.HP 4
.I <device>
The unique device ID (uint).
.HP 4
.I <k_heat>
The heating rate constant, k (float).
.HP 4
.I <t_ambient>
The ambient temperature, T_ambient (float).
.HP 4
.I <t_steady>
The estimated steady\-state temperature, T_steady (float),
which is the maximum expected temperature of the disk.
.HP 4
.I <rmse>
Root Mean Square Error of the fit (float).
.HP 4
.I <r_squared>
Coefficient of determination (R^2) of the fit (float).
.HP 4
.I <max_error>
Maximum absolute error of the fit (float).
.PD
.RE
.TP
.B thermal:spindown
Indicates that the thermal alarm limit has been reached, and
the process is initiating a disk spindown to begin the
cooldown procedure, preventing overheating.
.TP
.B thermal:cooldown:<sleep_time>
Indicates the duration of the cooldown waiting period after
spindown.
.RS 4
.PD 0
.HP 4
.I <sleep_time>
The total time the system will wait for
cooldown (uint, seconds).
.PD
.RE
.TP
.B thermal:spinup
Indicates that the cooldown period is complete, and the disks
are being spun back up to resume the operation.
.SH COMMAND STATUS TAGS 
This section describes the tags output with the \`status\` command.
.SS Summary Tags 
These tags provide general information about the array configuration
and overall state.
.TP
.B summary:block_size:<uint>
The size of a block in bytes. This is the unit of parity
protection.
.TP
.B summary:parity_block_count:<uint>
The total number of blocks allocated for all parity levels
combined.
.TP
.B summary:parity_block_total:<name>:<uint>
Total blocks available for a specific parity level (e.g.,
\`parity\`, \`2\-parity\`).
.TP
.B summary:parity_block_free:<name>:<uint>
Free blocks available for a specific parity level.
.TP
.B summary:parity_block_free_min:<uint>
The minimum number of free blocks across all parity levels.
This determines the maximum size of data that can be added.
.TP
.B summary:file_count:<uint>
Total number of files in the array.
.TP
.B summary:file_block_count:<uint>
Total number of data blocks used by files.
.TP
.B summary:fragmented_file_count:<uint>
Total number of fragmented files, meaning files whose blocks
are not contiguous.
.TP
.B summary:excess_fragment_count:<uint>
Total number of excess fragments (one less than the total fragments).
This is a measure of data fragmentation overhead.
.TP
.B summary:zerosubsecond_file_count:<uint>
Total number of files with a zero sub\-second timestamp. This
can occur on certain filesystems and may affect change detection.
.TP
.B summary:file_size:<uint>
Total size of all files in bytes.
.TP
.B summary:parity_size:<uint>
Total size of allocated parity blocks in bytes.
.TP
.B summary:parity_size_max:<uint>
Maximum possible parity size (allocated + min free) in bytes.
This is the effective maximum protection size.
.TP
.B summary:hash:<name>
The current hash algorithm in use (e.g., \`sha256\`).
.TP
.B summary:prev_hash:<name>
The previous hash algorithm used, if a rehash is in progress.
.TP
.B summary:best_hash:<name>
The best hash algorithm for optimal performance based on
system capabilities.
.TP
.B summary:total_wasted:<uint>
Total wasted space (space on data disks exceeding parity
capacity) in bytes.
.TP
.B summary:total_used:<uint>
Total used space by data files in bytes.
.TP
.B summary:total_free:<uint>
Total free space (usable by data) in bytes, limited by parity
capacity.
.TP
.B summary:total_use_percent:<uint>
Overall array use percentage.
.TP
.B summary:has_unsynced:<uint>
Count of blocks that are unsynced (need a sync), meaning their
parity data is out of date.
.TP
.B summary:has_unscrubbed:<uint>
Count of blocks that are unscrubbed (just synced), meaning they
have never been verified since the last sync.
.TP
.B summary:has_rehash:<uint>
Count of blocks needing a rehash, usually due to a content file
update or hash algorithm change.
.TP
.B summary:has_bad:<count>:<first>:<last>
Count of bad blocks, along with the first and last bad block index.
Bad blocks indicate data or parity corruption.
.TP
.B summary:scrub_oldest_days:<uint>
Days ago the oldest block was last scrubbed.
.TP
.B summary:scrub_median_days:<uint>
Days ago the median block was last scrubbed.
.TP
.B summary:scrub_newest_days:<uint>
Days ago the newest block was last scrubbed.
.TP
.B summary:exit:<status>
Logs the overall exit status of the command. The \`status\` is
one of the following:
.RS 4
.PD 0
.HP 4
.I ok
No issues. The array is fully synchronized and healthy.
.HP 4
.I bad
The array has some blocks marked as bad.
The array needs a \`\-e fix\` and and a \`\-p bad scrub\`
operation.
.HP 4
.I unsynced
The array has an interrupted sync.
The array needs another \`sync\` operation.
.PD
.RE
.SS Per\-Disk Tags 
These tags provide statistics for individual data disks. <name>
is the disk name.
.TP
.B summary:disk_file_count:<name>:<uint>
Number of files on the disk.
.TP
.B summary:disk_block_count:<name>:<uint>
Number of blocks used by files on the disk.
.TP
.B summary:disk_fragmented_file_count:<name>:<uint>
Number of fragmented files on the disk.
.TP
.B summary:disk_excess_fragment_count:<name>:<uint>
Number of excess fragments on the disk.
.TP
.B summary:disk_zerosubsecond_file_count:<name>:<uint>
Number of files with zero sub\-second timestamp on the disk.
.TP
.B summary:disk_file_size:<name>:<uint>
Total size of files on the disk in bytes.
.TP
.B summary:disk_block_allocated:<name>:<uint>
Highest block index used on the disk + 1.
.TP
.B summary:disk_block_total:<name>:<uint>
Total blocks on the disk (physical size).
.TP
.B summary:disk_block_free:<name>:<uint>
Free blocks on the disk.
.TP
.B summary:disk_block_max_by_space:<name>:<uint>
Total blocks by disk space (used + free blocks), representing
the physical limit of the disk.
.TP
.B summary:disk_block_max_by_parity:<name>:<uint>
Total blocks limited by parity space (parity size + min parity
free blocks).
This is the logical limit imposed by the parity files.
.TP
.B summary:disk_block_max:<name>:<uint>
Maximum usable blocks (minimum of \`..._by_space\` and \`..._by_parity\`).
.TP
.B summary:disk_space_wasted:<name>:<int>
Wasted space on the disk in bytes (positive if disk is larger
than usable parity space).
.TP
.B summary:disk_used:<name>:<uint>
Used space on the disk in bytes.
.TP
.B summary:disk_free:<name>:<uint>
Free usable space on the disk in bytes, limited by \`disk_block_max\`.
.TP
.B summary:disk_use_percent:<name>:<uint>
Disk use percentage relative to \`disk_block_max\`.
.SS File Timestamp Tags 
These tags list files with zero sub\-second timestamps.
.TP
.B zerosubsecond:<disk_name>:<file_path>
Lists files that have a zero sub\-second timestamp.
Up to 50 are logged per disk.
.SS Block Information Tags 
Status of all the blocks of the array.
.TP
.B block_count:<uint>
The total number of blocks in the array.
.TP
.B block:<index>:<time>:<used>:<unsynced>:<bad>:<rehash>
Status of a specific block.
Only produced when \`\-\-gui\-verbose\` option is used.
.RS 4
.PD 0
.HP 4
.I <index>
Block index.
.HP 4
.I <time>
Last scrub time (Unix timestamp). A value of 0 means
the block has never been scrubbed.
.HP 4
.I <used>
\`used\` if the block contains data, otherwise empty.
.HP 4
.I <unsynced>
\`unsynced\` if the block needs a sync, otherwise empty.
.HP 4
.I <bad>
\`bad\` if the block has errors, otherwise empty.
.HP 4
.I <rehash>
\`rehash\` if the block needs a rehash, otherwise empty.
.PD
.RE
.TP
.B block_noinfo:<index>:<used>:<unsynced>
Status of an unused block (no info recorded) in the content file.
Only produced when \`\-\-gui\-verbose\` option is used.
.RS 4
.PD 0
.HP 4
.I <index>
Block index.
.HP 4
.I <used>
\`used\` if the block contains data, otherwise empty.
.HP 4
.I <unsynced>
\`unsynced\` if the block needs a sync, otherwise empty.
.PD
.RE
.SS Scrub History Tags 
These tags provide details on the scrub/sync time distribution.
.TP
.B info_count:<uint>
Total number of info records about past scrub and sync
operations stored in the content file.
.TP
.B info_time:<time>:<count>:<status>
All the info records.
.RS 4
.PD 0
.HP 4
.I <time>
Unix timestamp of the scrub/sync.
.HP 4
.I <count>
Number of blocks processed at this timestamp.
.HP 4
.I <status>
\`scrubbed\` (for blocks verified to be correct) or
\`new\` (for synced blocks that haven\'t been scrubbed yet).
.PD
.RE
.TP
.B scrub_graph_range:<max_columns>:<max_height>
Dimensions of the scrub history graph obtained from the
\`info_time\` records. This provides the boundary for the
precomputed graph data available in the \`scrub_graph_bar\` tags.
.RS 4
.PD 0
.HP 4
.I <max_columns>
The number of columns in the graph (constant
GRAPH_COLUMN).
.HP 4
.I <max_height>
The maximum height (peak count) of blocks found
in any column (the highest sum of scrubbed and new blocks).
.PD
.RE
.TP
.B scrub_graph_bar:<index>:<days_ago>:<scrubbed>:<new>
Data for a column of the scrub history graph. Each column
represents a time period.
.RS 4
.PD 0
.HP 4
.I <index>
Column index. From 0 to max_columns \- 1.
.HP 4
.I <days_ago>
Days ago for this column\'s time range.
.HP 4
.I <scrubbed>
Count of scrubbed blocks in that day range.
.HP 4
.I <new>
Count of newly synced (unscrubbed) blocks in that day range.
.PD
.RE
.SH COMMAND SYNC/SCRUB TAGS 
Tags specific for the \`sync\` and \`scrub\` commands.
Also the error tags are possible.
.SS Summary Tags 
These tags provide summary statistics at the end of the command.
.TP
.B hash_summary:error_file:<count>
Logs the total count of file\-related errors that caused a
block to be skipped during the hashing phase. These are often
due to file changes (missing, size/time change) during the
sync operation. This happens only in \`sync\`.
.RS 4
.PD 0
.HP 4
.I <count>
Total number of file errors (uint).
.PD
.RE
.TP
.B summary:error_file:<count>
Logs the total count of file\-related errors encountered during
the process (e.g., missing files, file attribute changes).
.RS 4
.PD 0
.HP 4
.I <count>
The total number of file errors encountered (uint).
.PD
.RE
.TP
.B summary:error_io:<count>
Logs the total count of input/output errors encountered on
data or parity disks.
.RS 4
.PD 0
.HP 4
.I <count>
The total number of I/O errors encountered (uint).
.PD
.RE
.TP
.B summary:error_data:<count>
Logs the total count of \`silent data errors\` (data blocks
not matching their expected hash) encountered during the sync
process.
.RS 4
.PD 0
.HP 4
.I <count>
The total number of silent data errors encountered (uint).
.PD
.RE
.TP
.B summary:exit:<status>
Logs the overall exit status of the command. The \`status\` is
one of the following:
.RS 4
.PD 0
.HP 4
.I ok
No issues. The array is fully synchronized and healthy.
.HP 4
.I alert
Incomplete. Some files were skipped due to modifications
during execution or permission issues. No hardware risk.
.HP 4
.I error
Critical failure. Indicates serious issues like I/O failures
or silent data corruption. Requires immediate hardware
or filesystem inspection.
.PD
.RE
.SH COMMAND CHECK/FIX TAGS 
Tags specific for the \`check\` and \`fix\` commands.
Also the error tags are possible.
.SS Fixed/Recovered Tags 
These tags log successful repairs during fix operations.
.TP
.B fixed:<block_pos>:<disk_name>:<file_path>:<msg>
Indicates that a file was successfully fixed using parity data.
.RS 4
.PD 0
.HP 4
.I <block_pos>
The block position being processed (uint).
.HP 4
.I <disk_name>
The name of the disk.
.HP 4
.I <file_path>
The file path relative to disk root (escaped).
.HP 4
.I <msg>
A descriptive message indicating the nature of the fix
(e.g., \`Fixed size\`, \`Fixed data error at position...\`).
.PD
.RE
.TP
.B parity_fixed:<block_pos>:<parity>:<msg>
Indicates that corrupted parity data was successfully
recomputed and written.
.RS 4
.PD 0
.HP 4
.I <block_pos>
The block position being processed (uint).
.HP 4
.I <parity>
The name of the parity level (e.g., \`parity\`, \`2\-parity\`).
.HP 4
.I <msg>
A descriptive message indicating the nature of the fix
(e.g., \`Fixed data error\`).
.PD
.RE
.TP
.B empty_fixed:<disk_name>:<file_path>:<msg>
Logs successful recreation of a missing or corrupted empty file.
.RS 4
.PD 0
.HP 4
.I <disk_name>
The name of the disk.
.HP 4
.I <file_path>
The file path relative to disk root (escaped).
.HP 4
.I <msg>
A descriptive message indicating the nature of the fix
(e.g., \`Fixed empty file\`).
.PD
.RE
.TP
.B hardlink_fixed:<disk_name>:<link_path>:<msg>
Logs successful recreation of a hard link during fix operation.
.RS 4
.PD 0
.HP 4
.I <disk_name>
The name of the disk.
.HP 4
.I <link_path>
The hard link path relative to disk root (escaped).
.HP 4
.I <msg>
A descriptive message indicating the nature of the fix
(e.g., \`Fixed hardlink error\`).
.PD
.RE
.TP
.B symlink_fixed:<disk_name>:<link_path>:<msg>
Logs successful recreation of a symbolic link during fix operation.
.RS 4
.PD 0
.HP 4
.I <disk_name>
The name of the disk.
.HP 4
.I <link_path>
The symlink path relative to disk root (escaped).
.HP 4
.I <msg>
A descriptive message indicating the nature of the fix
(e.g., \`Fixed symlink error\`).
.PD
.RE
.TP
.B dir_fixed:<disk_name>:<dir_path>:<msg>
Logs successful recreation of a missing directory during fix
operation.
.RS 4
.PD 0
.HP 4
.I <disk_name>
The name of the disk.
.HP 4
.I <dir_path>
The directory path relative to disk root (escaped).
.HP 4
.I <msg>
A descriptive message indicating the nature of the fix
(e.g., \`Fixed dir error\`).
.PD
.RE
.SS Unrecoverable Error Tags 
These tags log errors that could not be recovered.
.TP
.B unrecoverable:<block_pos>:<disk_name>:<file_path>:<msg>
Indicates that a block error could not be fixed due to
insufficient parity or other recovery limitations.
.RS 4
.PD 0
.HP 4
.I <block_pos>
The block position being processed (uint).
.HP 4
.I <disk_name>
The name of the disk.
.HP 4
.I <file_path>
The file path relative to disk root (escaped).
.HP 4
.I <msg>
A descriptive message indicating the nature of the problem
(e.g., \`Unrecoverable error at position <file_pos>\`,
\`Unrecoverable unsynced error at position <file_pos>\`).
.PD
.RE
.TP
.B collision:<disk_name>:<file_path>:<collision_path>:<msg>
Logs that the modification time was not set on a recovered file to
avoid inode collision with another file.
.RS 4
.PD 0
.HP 4
.I <disk_name>
The name of the disk.
.HP 4
.I <file_path>
The file path relative to disk root (escaped).
.HP 4
.I <collision_path>
The path of the colliding file (escaped).
.HP 4
.I <msg>
A descriptive message indicating the nature of the problem
(e.g., \`Not setting modification time to avoid inode collision\`).
.PD
.RE
.SS File Status Tags 
These tags log the final status of files after processing.
.TP
.B status:unrecoverable:<disk_name>:<file_path>
Indicates that a file has unrecoverable errors and was renamed to
\`.unrecoverable\` (in fix mode) or cannot be recovered (in check mode).
.RS 4
.PD 0
.HP 4
.I <disk_name>
The name of the disk.
.HP 4
.I <file_path>
The file path relative to disk root (escaped).
.PD
.RE
.TP
.B status:recovered:<disk_name>:<file_path>
Logs that a file was successfully recovered during fix operation.
.RS 4
.PD 0
.HP 4
.I <disk_name>
The name of the disk.
.HP 4
.I <file_path>
The file path relative to disk root (escaped).
.PD
.RE
.TP
.B status:damaged:<disk_name>:<file_path>
Indicates that a file is damaged (in audit\-only mode, e.g., using \`check\`).
.RS 4
.PD 0
.HP 4
.I <disk_name>
The name of the disk.
.HP 4
.I <file_path>
The file path relative to disk root (escaped).
.PD
.RE
.TP
.B status:recoverable:<disk_name>:<file_path>
Logs that a file has errors but could be recovered in fix mode.
.RS 4
.PD 0
.HP 4
.I <disk_name>
The name of the disk.
.HP 4
.I <file_path>
The file path relative to disk root (escaped).
.PD
.RE
.TP
.B status:correct:<disk_name>:<file_path>
Indicates that a file passed all checks successfully (verbose mode only).
.RS 4
.PD 0
.HP 4
.I <disk_name>
The name of the disk.
.HP 4
.I <file_path>
The file path relative to disk root (escaped).
.PD
.RE
.SS Summary Tags 
These tags provide summary statistics at the end of the command.
.TP
.B summary:error:<error_count>
Logs the total number of errors encountered.
.RS 4
.PD 0
.HP 4
.I <error_count>
Total number of errors (uint).
.PD
.RE
.TP
.B summary:error_recovered:<recovered_count>
Logs the total number of errors successfully recovered (fix mode only).
.RS 4
.PD 0
.HP 4
.I <recovered_count>
Number of recovered errors (uint).
.PD
.RE
.TP
.B summary:error_unrecoverable:<unrecoverable_count>
Logs the total number of unrecoverable errors (not in audit\-only mode).
.RS 4
.PD 0
.HP 4
.I <unrecoverable_count>
Number of unrecoverable errors (uint).
.PD
.RE
.TP
.B summary:exit:<status>
Logs the overall exit status of the command. The \`status\` is one of
the following:
.RS 4
.PD 0
.HP 4
.I ok
Indicates that the operation completed with no errors.
.HP 4
.I recovered
Indicates that the operation completed with all
errors successfully recovered (fix mode only).
.HP 4
.I recoverable
Indicates that errors were found but are all
recoverable (check mode only).
.HP 4
.I unrecoverable
Indicates that unrecoverable errors were
found.
.HP 4
.I error
Indicates that errors were found (audit\-only mode).
.PD
.RE
.SH COMMAND LIST TAGS 
This section describes the tags output with the \`list\` command.
.SS List Tags 
These tags log details about individual files and links processed during
the listing operation.
.TP
.B file:<disk_name>:<subpath>:<size>:<mtime_sec>:<mtime_nsec>:<inode>
Logs details for a regular file found on a disk.
.RS 4
.PD 0
.HP 4
.I <disk_name>
The configured name of the disk.
.HP 4
.I <subpath>
The path of the file relative to the disk\'s root
(escaped).
.HP 4
.I <size>
The size of the file in bytes (uint).
.HP 4
.I <mtime_sec>
The file\'s modification time in seconds since the
Epoch (int).
.HP 4
.I <mtime_nsec>
The file\'s modification time nanosecond component
(uint).
.HP 4
.I <inode>
The file\'s inode number (uint).
.PD
.RE
.TP
.B link_<type>:<disk_name>:<subpath>:<linkto>
Logs details for a link found on a disk. The \`<type>\` component
varies based on the kind of link.
.RS 4
.PD 0
.HP 4
.I <type>
The type of link, one of: \`hardlink\`, \`symlink\`,
\`symdir\` (symlink to a directory), \`junction\`
(Windows\-specific reparse point).
.HP 4
.I <disk_name>
The configured name of the disk (string).
.HP 4
.I <subpath>
The path of the link relative to the disk\'s root
(escaped).
.HP 4
.I <linkto>
The target path of the link (escaped).
.PD
.RE
.SS Summary Tags 
These tags log final statistics about the entire listing operation.
.TP
.B summary:file_count:<count>
Logs the total number of regular files processed.
.RS 4
.PD 0
.HP 4
.I <count>
The total number of files (uint).
.PD
.RE
.TP
.B summary:file_size:<size>
Logs the total size of all regular files processed.
.RS 4
.PD 0
.HP 4
.I <size>
The cumulative size of all files (uint, bytes).
.PD
.RE
.TP
.B summary:link_count:<count>
Logs the total number of links processed (hardlinks, symlinks,
symdirs, junctions).
.RS 4
.PD 0
.HP 4
.I <count>
The total number of links (uint).
.PD
.RE
.TP
.B summary:exit:ok
Indicates a successful completion of the listing operation.
Note that if a fatal error happens, the program will abort,
and you won\'t get this tag.
.SH COMMAND DUP TAGS 
This section describes the tags output with the \`dup\` command.
.SS Duplicate Tags 
These tags log information about detected duplicate files and provide
a summary of the duplicate finding process. The content hash of the
whole file is used to determine duplicates.
.TP
.B dup:<diskname1>:<file_path1>:<diskname2>:<file_path2>:<size>: dup
Logs the information about a pair of duplicate files found.
The first file listed is the one just processed, and the second
file is the previously processed file that has the same content hash.
.RS 4
.PD 0
.HP 4
.I <diskname1>
The configured name of the disk containing the
newly processed duplicate file.
.HP 4
.I <file_path1>
The path of the newly processed duplicate file
relative to its disk\'s mount point (escaped).
.HP 4
.I <diskname2>
The configured name of the disk containing the
previously processed file that is the duplicate
of \`<file_path1>\`.
.HP 4
.I <file_path2>
The path of the previously processed duplicate file
relative to its disk\'s mount point (escaped).
.HP 4
.I <size>
The size of the duplicate file in bytes (uint). This
size corresponds to the file \`<file_path2>\`.
.PD
.RE
.SS Summary Tags 
These tags provide a final summary of the duplicate finding process.
.TP
.B summary:dup_count:<count>
Logs the total number of duplicate files found. A file is counted
as a duplicate if its hash matches a hash already seen.
.RS 4
.PD 0
.HP 4
.I <count>
The total count of duplicate files (uint).
.PD
.RE
.TP
.B summary:dup_size:<size>
Logs the total size of all duplicate files found. This size is
the sum of the sizes of all files considered duplicates.
.RS 4
.PD 0
.HP 4
.I <size>
The total size of duplicate files in gigabytes (uint).
.PD
.RE
.TP
.B summary:exit:<status>
Logs the overall exit status of the command. The \`status\` is one of
the following:
.RS 4
.PD 0
.HP 4
.I unique
Indicates that no duplicate files were found.
.HP 4
.I dup
Indicates that at least one duplicate file was found.
.PD
.RE
.SH COMMAND POOL TAGS 
This section describes the tags output with the \`pool\` command.
.TP
.B summary:link_count:<count>
Logs the total number of links created (symlinks, junctions).
.RS 4
.PD 0
.HP 4
.I <count>
The total number of links (uint).
.PD
.RE
.TP
.B summary:exit:ok
Indicates a successful completion of the pool operation.
Note that if a fatal error happens, the program will abort,
and you won\'t get this tag.
.SH COMMAND REHASH TAGS 
This section describes the tags output with the \`rehash\` command.
.SS Summary Tags 
These tags provide a final summary of the rehash scheduling process.
.TP
.B summary:exit:<status>
Logs the overall exit status of the command. The \`status\` is one of
the following:
.RS 4
.PD 0
.HP 4
.I scheduled
Indicates that a rehash operation has
been successfully scheduled. The rehash will be performed
incrementally in future \`sync\` or \`scrub\` commands.
.HP 4
.I already_in_progress
Indicates that that a rehash is already
in progress and cannot be scheduled again. This causes the
program to exit with a fatal error.
.HP 4
.I not_required
Indicates that the current hash algorithm is
already the \`best hash\` for the platform, and thus
a rehash is not required. This causes the program to
exit with a fatal error.
.PD
.RE
.SH COMMAND SMART AND PROBE TAGS 
This section describes the tags output by the \`smart\` and \`probe\`
commands. The main difference between the two is that \`probe\` doesn\'t
spin up the disk, so it won\'t be able to get all attributes if the
disk is spun down. The \`smart\` command, instead, will always get all
attributes, but with the risk of spinning up all disks.
.PP
Note that a \`<disk_name>\` may be associated with more \`<device_file>\`,
in case the logical disk uses more physical disks. In such a case,
you\'ll see multiple \`<attr>\` and \`<smart>\` tags for the same
\`<disk_name>\` but with different \`<device_file>\`. The exception is the
\`stat\` attrbute that is cumulative for all the devices part of the
disk.
.PP
In case of split parity, the parity name is followed by \`/N\` to indicate
the split index, where N starts from 0. The \`/0\` is always omitted.
.SS Attributes 
Tags logging specific disk identification and attribute values.
.TP
.B smart:<device_file>:<disk_name>[/<split_index>]
Logs the start of the SMART report for a device.
.RS 4
.PD 0
.HP 4
.I <device_file>
The file path of the device (e.g., /dev/sdb).
.HP 4
.I <disk_name>[/<split_index>]
The configured name of the disk.
In case of split parity, the parity name is followed
by \`/N\` to indicate the split index, where N starts
from 0. The \`/0\` is always omitted.
.PD
.RE
.TP
.B attr:<device_file>:<disk_name>[/<split_index>]:serial:<serial_number>
Logs the disk\'s serial number.
.RS 4
.PD 0
.HP 4
.I <serial_number>
The disk\'s serial number (escaped).
.PD
.RE
.TP
.B attr:<device_file>:<disk_name>[/<split_index>]:family:<family>
Logs the disk\'s model family string.
.RS 4
.PD 0
.HP 4
.I <family>
The disk\'s model family identifier (escaped).
.PD
.RE
.TP
.B attr:<device_file>:<disk_name>[/<split_index>]:model:<model>
Logs the disk\'s model string.
.RS 4
.PD 0
.HP 4
.I <model>
The disk\'s model identifier (escaped).
.PD
.RE
.TP
.B attr:<device_file>:<disk_name>[/<split_index>]:afr:<afr>:<prob>
Logs the estimated Annual Failure Rate (AFR) and the
probability of at least one failure in the next year based on
SMART attributes. The AFR is calculated using the SMART
attributes (5, 187, 188, 197, 198).
.RS 4
.PD 0
.HP 4
.I <afr>
The computed Annual Failure Rate (the average number
of failures you expect in a year) (float).
.HP 4
.I <prob>
The probability of at least one failure in the
next year (float).
.PD
.RE
.TP
.B attr:<device_file>:<disk_name>[/<split_index>]:size:<size_bytes>
Logs the size of the disk.
.RS 4
.PD 0
.HP 4
.I <size_bytes>
The disk size in bytes (uint).
.PD
.RE
.TP
.B attr:<device_file>:<disk_name>[/<split_index>]:error:<error_count>
Logs the total error count.
.RS 4
.PD 0
.HP 4
.I <error_count>
The total error count (uint).
.PD
.RE
.TP
.B attr:<device_file>:<disk_name>[/<split_index>]:rotationrate:<rate>
Logs the disk\'s rotation rate.
.RS 4
.PD 0
.HP 4
.I <rate>
The rotation rate. A value of 0 indicates a
solid\-state drive (SSD) or other non\-rotating medium.
A value of 1 indicates a rotational disk of unknown
precise speed. Values greater than 1 indicate the
rotational speed in RPM.
.PD
.RE
.TP
.B attr:<device_file>:<disk_name>[/<split_index>]:flags:<flags_decimal>:<flags_hex>
Logs the SMART status flags from the \`smartctl\` utility.
Per the smartctl manpage, these flags are bit\-mapped
to indicate specific issues like \`Command line did not parse\`,
\`Device could not be opened\`, or \`SMART status check
returned \'DISK FAILING\'\`.
.RS 4
.PD 0
.HP 4
.I <flags_decimal>
The raw flags value (uint, decimal).
.HP 4
.I <flags_hex>
The raw flags value (uint, hexadecimal).
.PD
.RE
.TP
.B attr:<device_file>:<disk_name>[/<split_index>]:<id>:<value_decimal>:<value_hex>
Logs the raw value of any assigned SMART attribute.
.RS 4
.PD 0
.HP 4
.I <id>
The SMART attribute ID (uint).
.HP 4
.I <value_decimal>
The raw attribute value (uint, decimal).
.HP 4
.I <value_hex>
The raw attribute value (uint, hexadecimal).
.PD
.RE
.TP
.B attr:<device_file>:<disk_name>[/<split_index>]:power:active
Logs that the device was confirmed to be in an active power
state after a status probe.
.TP
.B attr:<device_file>:<disk_name>[/<split_index>]:power:standby
Logs that the device was confirmed to be in a standby/spun\-down
state.
.TP
.B attr:<device_file>:<disk_name>[/<split_index>]:power:up
Logs a successful spin\-up operation via direct O_DIRECT
read.
.TP
.B attr:<device_file>:<disk_name>[/<split_index>]:power:down
Logs a successful spin\-down operation initiated via the
smartctl command.
.TP
.B stat:<disk_name>:<access_number>
Logs the total number of read and write accesses done on the
disk. This is a cumulative value that include all the devices
and split of the disk.
Comparing this number at different times, you can detect if the
disk was used during that time.
.RS 4
.PD 0
.HP 4
.I <access_number>
Total number of accesses (uint).
.PD
.RE
.SS Summary 
Tags logging the overall failure probabilities for the array.
.TP
.B summary:array_failure:<array_afr>:<array_prob>
Logs the total estimated failure rate for the entire array
(sum of individual disk AFRs) and the probability of at least
one failure in the next year.
.RS 4
.PD 0
.HP 4
.I <array_afr>
The sum of AFRs of all disks in the array (the
average number of failures you expect in a year) (float).
.HP 4
.I <array_prob>
The probability of at least one failure in
the next year (float).
.PD
.RE
.SH DEVICE STATUS TAGS 
These tags log the lifecycle of hardware interactions and external
command execution with the \`smartctl\` command.
.TP
.B device:<device_file>:<disk_name>[/<split_index>]:shell
Logs a failure in the command shell execution environment.
.RS 4
.PD 0
.HP 4
.I <device_file>
The system path to the device node.
.HP 4
.I <disk_name>[/<split_index>]
The configured name of the disk.
In case of split parity, the parity name is followed
by \`/N\` to indicate the split index, where N starts
from 0. The \`/0\` is always omitted.
.PD
.RE
.TP
.B device:<device_file>:<disk_name>[/<split_index>]:error:<errno>
Logs a low\-level system error during direct file operations.
This is triggered when open(), read(), or close()
calls fail during a spin\-up attempt.
.RS 4
.PD 0
.HP 4
.I <errno>
The standard integer error number provided by
the OS.
.PD
.RE
.TP
.B device:<device_file>:<disk_name>[/<split_index>]:error:abort
Logs that an external process (smartctl) failed to complete
normally, such as being terminated by a signal rather than
exiting.
.TP
.B device:<device_file>:<disk_name>[/<split_index>]:exit:<exit_code>
Logs that the external command (smartctl) returned a non\-zero
exit code that was not explicitly recognized as a valid state.
.RS 4
.PD 0
.HP 4
.I <exit_code>
The integer exit status returned by the
process (int).
.PD
.RE
.SH ERROR TAGS 
These tags report specific errors that occur on data disks during the
commands that access files and parities.
.TP
.B error[_io|_data]:<block>:<disk_name>:<file>:<msg>
Logs file access errors (open, read, file changed) during the
data disk read operation for parity calculation or verification.
.RS 4
.PD 0
.HP 4
.I _io
Indicates a physical Input/Output error.
The disk was unable to read or write a specific block,
typically signaling a failing sector or cable issue.
.HP 4
.I _data
Indicates the data was read successfully but failed
the checksum/hash verification. This signals \`silent\`
corruption or an unsuccessful parity match.
.HP 4
.I <block>
The zero\-based index of the block where the error occurred (uint).
.HP 4
.I <disk_name>
The name of the data disk.
.HP 4
.I <file>
The path (relative to the disk mount point) of the
file containing the block (escaped).
.HP 4
.I <msg>
A descriptive message indicating the nature of the
error (e.g., \`Open/Read/Write EIO error\`, \`Open/Read/Write error\`,
\`Data error at position <pos>, diff bits <diff>/<bits>\`).
.PD
.RE
.TP
.B parity_error[_io|_data]:<block>:<level>:<msg>
Logs errors during parity disk read or write operations.
.RS 4
.PD 0
.HP 4
.I _io
Indicates a physical Input/Output error.
The disk was unable to read or write a specific block,
typically signaling a failing sector or cable issue.
.HP 4
.I _data
Indicates the data was read successfully but failed
the checksum/hash verification. This signals \`silent\`
corruption or an unsuccessful parity match.
.HP 4
.I <block>
The zero\-based index of the block where the error occurred (uint).
.HP 4
.I <level>
The configuration name of the parity level (e.g.,
\`parity\`, \`2\-parity\`).
.HP 4
.I <msg>
A descriptive message indicating the nature of the
error (e.g., \`Read/Write EIO error\`, \`Read/Write error\`,
\`Data error, diff bits <diff>/<bits>\`).
.PD
.RE
.TP
.B hardlink_error:<disk_name>:<link_path>:<target_path>:<msg>
Indicates an error when attempting to access a hard link.
.RS 4
.PD 0
.HP 4
.I <disk_name>
The name of the disk.
.HP 4
.I <link_path>
The hard link path relative to disk root (escaped).
.HP 4
.I <target_path>
The target path of the hard link (escaped).
.HP 4
.I <msg>
A descriptive message indicating the nature of the
error (e.g., \`Hardlink stat error\`,
\`Hardlink error for not regular file\`, \`Hardlink to stat error\`,
\`Hardlink\-to error for not regular file\`,
\`Hardlink mismatch for different inode\`).
.PD
.RE
.TP
.B symlink_error:<disk_name>:<link_path>:<msg>
Indicates an error when attempting to access a symbolic link.
.RS 4
.PD 0
.HP 4
.I <disk_name>
The name of the disk.
.HP 4
.I <link_path>
The symlink path relative to disk root (escaped).
.HP 4
.I <msg>
A descriptive message indicating the nature of the
error (e.g., \`Symlink read error\`,
\`Symlink data error \'<actual>\' instead of \'<expected>\'\`).
.PD
.RE
.TP
.B dir_error:<disk_name>:<dir_path>:<msg>
Indicates an error when attempting to access a directory.
.RS 4
.PD 0
.HP 4
.I <disk_name>
The name of the disk.
.HP 4
.I <dir_path>
The directory path relative to disk root (escaped).
.HP 4
.I <msg>
A descriptive message indicating the nature of the
error (e.g., \`Dir stat error\`, \`Dir error for not directory\`).
.PD
.RE
.TP
.B outofparity:<disk_name>:<file_path>
Logs that a file\'s blocks extend beyond the available parity
space, indicating that the parity files are too small to
protect all data. This occurs when data requires more parity
than is available on the parity disk(s) and is a critical
warning.
.RS 4
.PD 0
.HP 4
.I <disk_name>
The name of the disk containing the file.
.HP 4
.I <file_path>
The file path relative to the disk root (escaped).
.PD
.RE