Trouble assembling multipath md devices between two nodes who see the same LUNs.
Hello,
I have two nodes, hostA and hostB, both of them see the same 4 multipath LUNs.
md0 to md4 are thus visible to both the hosts, (yeah, they both do not write to thoe md devices at the same time, hostB mounts them only when hostA is down or has crashed, and viceversa.)
It works for a while.
While testing, the latest we have seen is, after md devices are stopped on hostA, hostB cannot start the md devices, as the uuid changes, and comes back with a message in --verbose mode:
mdadm: /dev/sdc has wrong uuid
mdadm: no devices found for /dev/md0
Tried copying over the mdadm.conf with the latest uuids from hostA, still hostB cannot assemble them. I have to re-create the md devices on hostB eventually, then after a while, hostA starts to act up: it simply refuses to assemble.
Is there a way I can circumvent this problem? I am running rhel 3.0 (AS and ES), and we're on mdadm - v1.5.0 - 22 Jan 2004, from Redhat's mdadm-1.5.0-9 rpm.
Thank you so much in advance,
--AM
Quoted 10 lines · Anu Matthew
Hello,
I have two nodes, hostA and hostB, both of them see the same 4 multipath LUNs.
md0 to md4 are thus visible to both the hosts, (yeah, they both do not write to thoe md devices at the same time, hostB mounts them only when hostA is down or has crashed, and viceversa.)
It works for a while.
md multipath has on-disk metadata and modifies it. md is NOT cluster-safe for concurrent activation.
Sincerely,
Lars Marowsky-Brée <[email protected]>
Signature · 8 lines
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