- Red Hat Enterprise Linux (RHEL) 5, 6, 7
- Messages similar to the following are seen in the logs:
kernel: lost page write due to I/O error on dm-29 --- kernel: Buffer I/O error on dev sdc, logical block 4, lost async page write kernel: Buffer I/O error on dev sdc, logical block 5, lost async page write
- Should I be concerned about messages indicating
lost page write due to I/O error?
- Check the switch and storage array controllers for errors or link failures
- Review the messages prior to these in
/var/log/messagesfor clues as to what may have caused the lost page write (these are usually accompanied by more descriptive errors).
This is a serious error and potentially indicates data loss has occurred. There can be many root causes, depending on the specific storage configuration:
If SAN storage was involved, paths to LUNs may have been lost from a cable pull, storage reconfiguration, switches, link failure, or disk overprovisioning.
device-mapper-multipathwas in use, all paths may have been lost, and
queue_if_no_pathwas not explicitly set on the multipath map, or
no_path_retryexhausted all retries. To determine if one of these was the case:
queue_if_no_pathwill be displayed in the "features" in the output of
multipath -llif it is configured for that device:
mpatha (360014380125989a10000400001300000) dm-6 HP,HSV300 size=1.0G features='1 queue_if_no_path' hwhandler='0' wp=rw `-+- policy='round-robin 0' prio=50 status=active |- 0:0:0:7 sdg 8:96 active ready running `- 0:0:3:7 sdah 66:16 active ready running
no_path_retrymay be specified in
/etc/multipath.confin a device section. It may also be a default setting for that device type, and if so, should be listed in
/usr/share/doc/device-mapper-multipath-<version>/multipath.conf.defaults. Search for your device vendor/product and see if that device block contains a value for
no_path_retry. If it is not listed in either location, then
no_path_retryis not enabled on the device.
If multipath is not in use, a SCSI device
WRITEcommand timed out.
asyncread-operation would be serviced from the page cache and if the page which needs to be read from the cache is not yet marked as
PG_uptodatethen such read operation would fail and would need filesystem's journaling capabilities to sync the read-cache for marking those pages as valid once again.
Follow basic steps for data recovery, such as umounting any filesystem involved with the device, and running
- Red Hat Enterprise Linux
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