[CentOS] Multipathing with Sun 7310

[James A. Peltier]

On Thu, 27 May 2010, Jens Neu wrote:

> Dear list,
> 
> we have a relatively new Sun Storage 7310, where we connect CentOS 5.5 Servers (IBM LS21/LS41 Blades) via Brocade Switches, 4GBit FC. The Blades boot from SAN via qla2xxx, and have no harddisks at all. We
> want them to use multipathing from the very beginning, so /boot and / are already seen by multipathd. Problem is, that the Sun 7310 has two storage heads which run in active/passive mode. BUT the
> multipathd thinks, they are active/active and therefor shows half the available paths as faulty (multipath -ll below)
> While this probably gives me the redundancy that is desired, it is a relatively messy situation, since it will be unnecessary hard to detect real path failures and the OS is complaining about "readsector0
> checker reports path is down" which gives me >40M/24h /var/log/messages garbage.
> Any hints for a reasonable configuration? Unfortunately the Sun 7310 is rather new, so almost nothing shows up on google... even less for RHEL/CentOS :-(
> 
> regards from Berlin
> Jens
> 
> [root at dev-db1 tmp]# multipath -ll
> sdaa: checker msg is "readsector0 checker reports path is down"
> sdab: checker msg is "readsector0 checker reports path is down"
> sdac: checker msg is "readsector0 checker reports path is down"
> sdad: checker msg is "readsector0 checker reports path is down"
> sdd: checker msg is "readsector0 checker reports path is down"
> sdh: checker msg is "readsector0 checker reports path is down"
> sdl: checker msg is "readsector0 checker reports path is down"
> sdp: checker msg is "readsector0 checker reports path is down"
> sdq: checker msg is "readsector0 checker reports path is down"
> sdr: checker msg is "readsector0 checker reports path is down"
> sds: checker msg is "readsector0 checker reports path is down"
> sdt: checker msg is "readsector0 checker reports path is down"
> sdu: checker msg is "readsector0 checker reports path is down"
> sdv: checker msg is "readsector0 checker reports path is down"
> sdx: checker msg is "readsector0 checker reports path is down"
> sdz: checker msg is "readsector0 checker reports path is down"
> mpath0 (3600144f0fdf58b5c00004bc738070001) dm-0 SUN,Sun Storage 7310
> [size=50G][features=0][hwhandler=0][rw]
> \_ round-robin 0 [prio=1][active]
>  \_ 0:0:1:0 sda  8:0    [active][ready]
> \_ round-robin 0 [prio=1][enabled]
>  \_ 1:0:0:0 sde  8:64   [active][ready]
> \_ round-robin 0 [prio=1][enabled]
>  \_ 0:0:2:0 sdi  8:128  [active][ready]
> \_ round-robin 0 [prio=1][enabled]
>  \_ 1:0:1:0 sdm  8:192  [active][ready]
> \_ round-robin 0 [prio=0][enabled]
>  \_ 0:0:3:0 sdq  65:0   [failed][faulty]
> \_ round-robin 0 [prio=0][enabled]
>  \_ 1:0:2:0 sdr  65:16  [failed][faulty]
> \_ round-robin 0 [prio=0][enabled]
>  \_ 0:0:4:0 sdx  65:112 [failed][faulty]
> \_ round-robin 0 [prio=0][enabled]
>  \_ 1:0:3:0 sdz  65:144 [failed][faulty]

There may be a vendor specific RDAC driver needed to properly interface 
with the 7310 unit or with the vendor HBA.  Check and see as that driver 
may properly hide the hardware multiple paths, etc.

-- 
James A. Peltier
Systems Analyst (FASNet), VIVARIUM Technical Director
HPC Coordinator
Simon Fraser University - Burnaby Campus
Phone   : 778-782-6573
Fax     : 778-782-3045
E-Mail  : jpeltier at sfu.ca
Website : http://www.fas.sfu.ca | http://vivarium.cs.sfu.ca
           http://blogs.sfu.ca/people/jpeltier
MSN     : subatomic_spam at hotmail.com

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