Hi all, Konrad Rzeszutek wrote: > On Thu, Jul 02, 2009 at 01:44:18PM +0200, Hannes Reinecke wrote: >> Christian May wrote: >>> Hi, >>> >>> I've setup an IBM z10 LPAR (mainframe server) with 2.6.30-kernel. >>> Attached to the System z10 was an IBM DS8000 storage server. 10x SCSI >>> LUNs were assigned to LPAR via two pathes: >>> >>> Example: >>> 36005076303ffc1040000000000001269 dm-9 IBM,2107900 >>> size=1.0G features='1 queue_if_no_path' hwhandler='0' wp=rw >>> `-+- policy='round-robin 0' prio=-2 status=active >>> |- 0:0:0:1080639506 sdw 65:96 active undef running >>> `- 1:0:1:1080639506 sdt 65:48 active undef running >>> >>> Special parameter setting: dev_loss_tmo=90sec; fast_io_fail_tmo=5sec >>> >>> multipath tools: multipath-tools v0.4.9 (04/04, 2009) >>> device-mapper: device-mapper-1.02.27-7.fc10.s390x, >>> device-mapper-libs-1.02.27-7.fc10.s390x >>> >>> When removing a remote port (disabling a port on the BROCADE FC switch) >>> one path failed. >>> >>> root@h42lp26/ESAME:~] >>>> multipath -l >>> 36005076303ffc1040000000000001268 dm-8 , >>> size=1.0G features='1 queue_if_no_path' hwhandler='0' wp=rw >>> `-+- policy='round-robin 0' prio=-2 status=active >>> |- #:#:#:# - #:# failed undef running >>> `- 1:0:1:1080573970 sdr 65:16 active undef running >>> >>> After a while (>90sec) SCSI LUNs were removed from system: >>> >> [ .. ] >>> When re-enabling the path, SCSI LUNS were reassigned to system but path >>> didn't recover: >>> >> [ .. ] >> >>> >>> [root@h42lp26/ESAME:~] >>>> multipath -l >>> 36005076303ffc1040000000000001268 dm-8 , >>> size=1.0G features='1 queue_if_no_path' hwhandler='0' wp=rw >>> `-+- policy='round-robin 0' prio=-2 status=active >>> |- #:#:#:# - #:# failed undef running >>> `- 1:0:1:1080573970 sdr 65:16 active undef running >>> >>> >>> Running "multipath" command will recover the failed path but that's not >>> way it should be...can somebody help to fix this? Why is the path not >>> recovered automatically? >>> >> It should, really. >> >> The problem is that the paths have _not_ been reconnected; >> the hashes indicates that the in-kernel multipath code references >> a device for which no information is available. >> And the new device has _not_ been reconnected, as otherwise >> you'd end up with _three_ paths here. >> >> Probably missing udev integration. > > Could also be a race condition that is present in SLES10 + RHEL5 > kernels. Where the SysFS directories are created (and the udev event it > sent out), but the kernel hasn't populated the SysFS directories. So > when multipathd tries to read them it finds no pertient information and > shoves it off to the 'orphan' state. > Really? With SLES10? Have you actually observed this? We're running multipath _after_ udev has processed the event. And udev already waited for sysfs, so we should be safe there. It might be applicable to mainline multipath-tools, but the SLES10 one ... I'd be surprised. Well, reasonably surprised. multipath keeps on throwing an amazing number of issues still. Do you have more information here? Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Markus Rex, HRB 16746 (AG Nürnberg) -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
