96 lines
2.8 KiB
Groff
96 lines
2.8 KiB
Groff
.\" -*- nroff -*-
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.\" Copyright Piergiorgio Sartor and others.
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.\" This program is free software; you can redistribute it and/or modify
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.\" it under the terms of the GNU General Public License as published by
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.\" the Free Software Foundation; either version 2 of the License, or
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.\" (at your option) any later version.
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.\" See file COPYING in distribution for details.
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.TH RAID6CHECK 8 "" v1.0.0
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.SH NAME
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raid6check \- check MD RAID6 device for errors
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.I aka
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Linux Software RAID
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.SH SYNOPSIS
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.BI raid6check " <raid6 device> <start stripe> <number of stripes>"
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.SH DESCRIPTION
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RAID6 devices in which one single component drive has errors can use
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the double parity in order to find out which component drive.
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The "raid6check" tool checks, for each stripe, the double parity
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consistency, reports mismatches and, if possible, which
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component drive has the mismatch.
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Since it works at stripe level, it can report different drives with
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mismatches at different stripes.
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"raid6check" requires a non-degraded RAID6 MD device as first
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parameter, a starting stripe (usually 0) and the number of stripes
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to be checked.
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If this third parameter is also 0, it will check the array up to
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the end.
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"raid6check" will start printing information about the RAID6, then
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for each stripe, it will report the parity rotation status.
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In case of parity mismatches, "raid6check" reports, if possible,
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which component drive could be responsible. Otherwise it reports
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that it is not possible to find the component drive.
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If the given MD device is not a RAID6, "raid6check" will, of
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course, not continue.
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If the RAID6 MD device is degraded, "raid6check" will report
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an error and it will not proceed further.
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No write operations are performed on the array or the components.
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Furthermore, the checked array can be online and in use during
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the operation of "raid6check".
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.SH EXAMPLES
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.B " raid6check /dev/md0 0 0"
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.br
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This will check /dev/md0 from start to end.
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.B " raid6check /dev/md3 0 1"
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.br
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This will check the first stripe of /dev/md3.
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.B " raid6check /dev/md1 1000 0"
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.br
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This will check /dev/md1 from stripe 1000 up to the end.
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.B " raid6check /dev/m127 128 256"
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.br
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This will check 256 stripes of /dev/md127 starting from stripe 128.
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.B " raid6check /dev/md0 0 0 | grep -i error > md0_err.log"
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.br
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This will check /dev/md0 completely and create a log file only
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with errors, if any.
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.SH FILES
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"raid6check" uses directly the component drives as found in /dev.
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Furthermore, the sysfs interface is needed in order to find out
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the RAID6 parameters.
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.SH BUGS
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Negative parameters can lead to unexpected results.
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It is not clear what will happen if the RAID6 MD device gets
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degraded during the check.
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.PP
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The latest version of
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.I raid6check
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should always be available from
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.IP
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.B https://www.kernel.org/pub/linux/utils/raid/mdadm/
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.PP
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Related man pages:
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.PP
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.IR mdadm (8)
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.IR mdmon (8),
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.IR mdadm.conf (5),
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.IR md (4).
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