From 946b54554e13d6a97940df936123855e0a305abc Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 24 Feb 2023 15:34:34 +0100 Subject: Adding upstream version 4.2. Signed-off-by: Daniel Baumann --- raid6check.8 | 96 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 96 insertions(+) create mode 100644 raid6check.8 (limited to 'raid6check.8') diff --git a/raid6check.8 b/raid6check.8 new file mode 100644 index 0000000..8999ca8 --- /dev/null +++ b/raid6check.8 @@ -0,0 +1,96 @@ +.\" -*- nroff -*- +.\" Copyright Piergiorgio Sartor and others. +.\" This program is free software; you can redistribute it and/or modify +.\" it under the terms of the GNU General Public License as published by +.\" the Free Software Foundation; either version 2 of the License, or +.\" (at your option) any later version. +.\" See file COPYING in distribution for details. +.TH RAID6CHECK 8 "" v1.0.0 +.SH NAME +raid6check \- check MD RAID6 device for errors +.I aka +Linux Software RAID + +.SH SYNOPSIS + +.BI raid6check " " + +.SH DESCRIPTION +RAID6 devices in which one single component drive has errors can use +the double parity in order to find out which component drive. +The "raid6check" tool checks, for each stripe, the double parity +consistency, reports mismatches and, if possible, which +component drive has the mismatch. +Since it works at stripe level, it can report different drives with +mismatches at different stripes. + +"raid6check" requires a non-degraded RAID6 MD device as first +parameter, a starting stripe (usually 0) and the number of stripes +to be checked. +If this third parameter is also 0, it will check the array up to +the end. + +"raid6check" will start printing information about the RAID6, then +for each stripe, it will report the parity rotation status. +In case of parity mismatches, "raid6check" reports, if possible, +which component drive could be responsible. Otherwise it reports +that it is not possible to find the component drive. + +If the given MD device is not a RAID6, "raid6check" will, of +course, not continue. + +If the RAID6 MD device is degraded, "raid6check" will report +an error and it will not proceed further. + +No write operations are performed on the array or the components. +Furthermore, the checked array can be online and in use during +the operation of "raid6check". + +.SH EXAMPLES + +.B " raid6check /dev/md0 0 0" +.br +This will check /dev/md0 from start to end. + +.B " raid6check /dev/md3 0 1" +.br +This will check the first stripe of /dev/md3. + +.B " raid6check /dev/md1 1000 0" +.br +This will check /dev/md1 from stripe 1000 up to the end. + +.B " raid6check /dev/m127 128 256" +.br +This will check 256 stripes of /dev/md127 starting from stripe 128. + +.B " raid6check /dev/md0 0 0 | grep -i error > md0_err.log" +.br +This will check /dev/md0 completely and create a log file only +with errors, if any. + +.SH FILES + +"raid6check" uses directly the component drives as found in /dev. +Furthermore, the sysfs interface is needed in order to find out +the RAID6 parameters. + +.SH BUGS +Negative parameters can lead to unexpected results. + +It is not clear what will happen if the RAID6 MD device gets +degraded during the check. + +.PP +The latest version of +.I raid6check +should always be available from +.IP +.B https://www.kernel.org/pub/linux/utils/raid/mdadm/ +.PP +Related man pages: +.PP +.IR mdadm (8) +.IR mdmon (8), +.IR mdadm.conf (5), +.IR md (4). -- cgit v1.2.3