diff options
| author | NeilBrown <neilb@suse.com> | 2016-11-25 00:55:49 +0100 |
|---|---|---|
| committer | Jes Sorensen <Jes.Sorensen@redhat.com> | 2016-11-28 14:50:36 +0100 |
| commit | 71574efb077131701b3da874df0045f259ca3448 (patch) | |
| tree | ef0279065d848d79848e164a5acdf4317a952c22 /mdadm.8.in | |
| parent | Increase buffer for sysfs disk state (diff) | |
| download | mdadm-71574efb077131701b3da874df0045f259ca3448.tar.xz mdadm-71574efb077131701b3da874df0045f259ca3448.zip | |
Add failfast support.
Allow per-device "failfast" flag to be set when creating an
array or adding devices to an array.
When re-adding a device which had the failfast flag, it can be removed
using --nofailfast.
failfast status is printed in --detail and --examine output.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Diffstat (limited to 'mdadm.8.in')
| -rw-r--r-- | mdadm.8.in | 32 |
1 files changed, 31 insertions, 1 deletions
@@ -747,7 +747,7 @@ subsequent devices listed in a .BR \-\-create , or .B \-\-add -command will be flagged as 'write-mostly'. This is valid for RAID1 +command will be flagged as 'write\-mostly'. This is valid for RAID1 only and means that the 'md' driver will avoid reading from these devices if at all possible. This can be useful if mirroring over a slow link. @@ -762,6 +762,25 @@ mode, and write-behind is only attempted on drives marked as .IR write-mostly . .TP +.BR \-\-failfast +subsequent devices listed in a +.B \-\-create +or +.B \-\-add +command will be flagged as 'failfast'. This is valid for RAID1 and +RAID10 only. IO requests to these devices will be encouraged to fail +quickly rather than cause long delays due to error handling. Also no +attempt is made to repair a read error on these devices. + +If an array becomes degraded so that the 'failfast' device is the only +usable device, the 'failfast' flag will then be ignored and extended +delays will be preferred to complete failure. + +The 'failfast' flag is appropriate for storage arrays which have a +low probability of true failure, but which may sometimes +cause unacceptable delays due to internal maintenance functions. + +.TP .BR \-\-assume\-clean Tell .I mdadm @@ -1452,6 +1471,17 @@ that had a failed journal. To avoid interrupting on-going write opertions, .B \-\-add-journal only works for array in Read-Only state. +.TP +.BR \-\-failfast +Subsequent devices that are added or re\-added will have +the 'failfast' flag set. This is only valid for RAID1 and RAID10 and +means that the 'md' driver will avoid long timeouts on error handling +where possible. +.TP +.BR \-\-nofailfast +Subsequent devices that are re\-added will be re\-added without +the 'failfast' flag set. + .P Each of these options requires that the first device listed is the array to be acted upon, and the remainder are component devices to be added, |