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Buffer I/O messages from multipath devices.

skt_skt
Honored Contributor

Buffer I/O messages from multipath devices.


have a problem with multipath..
"Buffer I/O" mmessages are appearing in messages file for standby paths/devices.

Apr 5 23:00:02 hrdl2d kernel: Device sdb not ready.
Apr 5 23:00:02 hrdl2d kernel: end_request: I/O error, dev sdb, sector 0
Apr 5 23:00:02 hrdl2d kernel: Buffer I/O error on device sdb, logical block 0
Apr 5 23:00:02 hrdl2d kernel: Device sdb not ready.
Apr 5 23:00:02 hrdl2d kernel: end_request: I/O error, dev sdb, sector 0
Apr 5 23:00:02 hrdl2d kernel: Buffer I/O error on device sdb, logical block 0
Apr 5 23:00:02 hrdl2d kernel: Device sdb not ready.
Apr 5 23:00:02 hrdl2d kernel: end_request: I/O error, dev sdb, sector 0

Apr 10 05:21:35 hrdl2d kernel: Buffer I/O error on device sdh, logical block 0
Apr 10 05:21:35 hrdl2d kernel: Buffer I/O error on device sdh, logical block 1



In the below o/p "1" indicates the current/active paths.

Red Hat Enterprise Linux AS release 4 (Nahant Update 7)

Linux hstname 2.6.9-78.ELsmp #1 SMP Wed Jul 9 15:46:26 EDT 2008 x86_64 x86_64 x86_64 GNU/Linux

device-mapper-multipath-0.4.5-31.el4
~]# multipathd -k show config
multipathd> show paths

#:#:#:# hdc 22:0 [faulty] [orphan]
3:0:0:0 sdb 8:16 [active][ready] X................... 1/20
3:0:0:1 sdc 8:32 [active][ready] X................... 1/20
3:0:0:2 sdd 8:48 1 [active][ready] X................... 1/20
3:0:0:3 sde 8:64 [active][ready] X................... 1/20
3:0:1:0 sdf 8:80 1 [active][ready] X................... 1/20
3:0:1:1 sdg 8:96 1 [active][ready] X................... 1/20
3:0:1:2 sdh 8:112 [active][ready] X................... 1/20
3:0:1:3 sdi 8:128 1 [active][ready] X................... 1/20

multipathd>


Do you see the similar problems? Or i have a configuration issue??
5 REPLIES
Steven E. Protter
Exalted Contributor

Re: Buffer I/O messages from multipath devices.

Shalom,

This really isn't a problem.

The messages log but effect nothing. If this is really a fail over path it will be there when the primary is offline.

It happens when disk paths are discovered and discarded.

SEP
Steven E Protter
Owner of ISN Corporation
http://isnamerica.com
http://hpuxconsulting.com
Sponsor: http://hpux.ws
Twitter: http://twitter.com/hpuxlinux
Founder http://newdatacloud.com
Ed Barnum
Advisor

Re: Buffer I/O messages from multipath devices.

What type of storage array/firmware is this system using?
skt_skt
Honored Contributor

Re: Buffer I/O messages from multipath devices.

EMC clariion

Model: CX500
Agent Rev: 6.26.7 (0.87)
Revision: 2.26.500.5.014
Ed Barnum
Advisor

Re: Buffer I/O messages from multipath devices.

Was just curious, as HP only supports device mapper with their active/active arrays.
skt_skt
Honored Contributor

Re: Buffer I/O messages from multipath devices.

No "HP" relation here. LINUX os and IBM hardware and EMC array