infra-docs-fpo/modules/sysadmin_guide/pages/infra-raidmismatch.adoc
Michal Konečný df7cb54128 Review infra-raidmismatch SOP
Signed-off-by: Michal Konečný <mkonecny@redhat.com>
2021-09-02 15:12:52 +02:00

68 lines
1.4 KiB
Text

= Infrastructure Raid Mismatch Count SOP
What to do when a raid device has a mismatch count
== Contents
* <<_contact_information>>
* <<_description>>
* <<_correction>>
== Contact Information
Owner::
Fedora Infrastructure Team
Contact::
#fedora-admin, sysadmin-main
Location::
All
Servers::
Physical hosts
Purpose::
Provides database connection to many of our apps.
== Description
In some situations a raid device may indicate there is a count mismatch
as listed in:
....
/sys/block/mdX/md/mismatch_cnt
....
Anything other than 0 is considered not good. Though if the number is
low it's probably nothing to worry about. To correct this situation try
the directions below.
== Correction
More than anything these steps are to A) Verify there is no problem and
B) make the error go away. If step 1 and step 2 don't correct the
problems, *PROCEED WITH CAUTION*. The steps below, however, should be
relatively safe.
Issue a repair (replace mdX with the questionable raid device):
....
echo repair > /sys/block/mdX/md/sync_action
....
Depending on the size of the array and disk speed this can take a while.
Watch the progress with:
....
cat /proc/mdstat
....
Issue a check. It's this check that will reset the mismatch count if
there are no problems. Again replace mdX with your actual raid device:
....
echo check > /sys/block/mdX/md/sync_action
....
Just as before, you can watch the progress with:
....
cat /proc/mdstat
....