RedHat 5 Multipath using SAN attached disk
Hi Everyone,
I have set up a RHEL5 server with combination of internal and SAN attached disk. The problem is not with the initial configuration, that all works, but with the re-creating of the multipath device when the fibre channel fails. The configuration of the md is: /etc/mdadm.conf DEVICE /dev/sd[ab]1 DEVICE /dev/sd[ab]2 DEVICE /dev/sd[ab]3 DEVICE /dev/sd[ab]4 ARRAY /dev/md0 level=multipath devices=/dev/sda1,/dev/sdb1 auto=md spares=0 ARRAY /dev/md1 level=multipath devices=/dev/sda2,/dev/sdb2 auto=md spares=0 ARRAY /dev/md2 level=multipath devices=/dev/sda3,/dev/sdb3 auto=md spares=0 ARRAY /dev/md3 level=multipath devices=/dev/sda4,/dev/sdb4 auto=md spares=0 Initially used mdadm -C /dev/md1 --level=multipath --raid-devices=2 --auto=md --spares=0 to create device. To test the fail-over capability I simply removed one of the FC cables from the server. fail-over worked as I had expected. When I reconnected the FC I had to remove and re-add the device to the md: mdadm --manage /dev/md1 --fail /dev/sdb2 --remove /dev/sdb2 mdadm --manage /dev/md1 --re-add /dev/sdb2 I know the "--fail" was unnecessary as it had already failed, but for completeness it certainly didn't hurt. When I re-add the disk to the md it only adds it as a hot-spare: mdadm --detail /dev/md1 /dev/md1: Version : 00.90.03 Creation Time : Fri Dec 21 21:52:21 2007 Raid Level : multipath Array Size : 97667072 (93.14 GiB 100.01 GB) Raid Devices : 2 Total Devices : 2 Preferred Minor : 1 Persistence : Superblock is persistent Update Time : Thu Jan 3 16:30:14 2008 State : clean, degraded Active Devices : 1 Working Devices : 1 Failed Devices : 1 Spare Devices : 0 UUID : f7cb73e7:fa191968:125d5509:f0338bc6 Events : 0.11 Number Major Minor RaidDevice State 0 0 0 0 removed 1 8 2 1 active sync /dev/sda2 2 8 18 - hot spare /dev/sdb2 So, after all this, my question is how do I tell the md that /dev/sdb2 is not a hot-spare but is device number 0 (or 1) and should have a state of "active sych" same as /dev/sda2?? If I reboot it all comes up as it should with no hot-spare and both devices are "active sync", but I had hoped there would be a way of doing this without a reboot. Thanks in advance for any responses, Mal |
I know this is a bit older, but I figured I would give it a bump. I apologize for resurrecting this.
I have the exact same problem. I've been messing with it now for a couple days... so any help would be greatly appreciated. Again, a reboot would resolve the issue, but this is a fairly active system and reboots have to be scheduled and must receive management approval. Any Help? |
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