RHEL6: DM Multipath device partitioning
Hi All
Has anyone expereniced any issues with trying to partition a DM multipath disk device under RHEL6?
At the moment, I'm noting that some of the individual devices paths will not pick up partition table changes made on against either the multipath device or (as Redhat has previously suggested) against another one of the paths.
partprobe, kpartx and partx all fail to propergate out partition information to the other paths....Reboot seems to be the only sure way, which is not ideal on a production system.
Seems a lot less reliable that partitioning a DM multipath device under RHEL5.
Appreciate your thoughts and suggestions.
Cheers
Jason
Responses
Hi Jason,
That's quite curious indeed. It sounds like you've seen this article, since you've run kpartx and partx. Just wondering whether you're running something like 'partx -va /dev/mapper/mpath0' or 'partx -va /dev/sdb'?
I'd be curious to hear what others in the community have done when faced with this too.
Cheers,
Rohan
Hey,
I used kpartex, and its updated my partitions tables. Little bit curious about your issue.
rgds,
Shyfur
I have not experienced the specific situation you are currently in, but I have been in a situation where we provided SAN devices (which were incorrect) and had them removed and then re-added as different devices. Which REALLY messes up the multipath "status". Here are a few things from my process that might be relevant to your troubleshooting. I wonder if multipath -f <device> would help the OS recognize the changes (-f can have negative effects on your system - test this on a non-prod system for your use case).
DISCLAIMER: please research and validate these commands and the impact of running them.
# tail -f /var/log/messages
# multipath -ll
# echo "- - -" > /sys/class/scsi_host/host#/scan
# rescan-scsi-bus.sh
#! /bin/sh
# return all offline scsi devices to the running state
for d in /sys/block/sd*/device/state; do if [ `cat $d` = "offline" ]; then echo running > $d; fi; done
Enable additional logging in the lpfc driver:
# echo 0x1f > /sys/module/lpfc/lpfc_log_verbose
Enable extra logging for the scsi-subsystem:
# echo 7 > /sys/module/scsi_mod/scsi_logging_level
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