Re: SCSI disk IO problem with JBOD

[Erich Weiler <weiler@soe.ucsc.edu>]

Hi Stan,

Thanks for replying!

>> We have a Dell R610 server running CentOS 6.3 (kernel
>> 2.6.32-279.2.1.el6.x86_64).  We installed a LSI 9201-16e SAS HBA in it,
>> upgraded to the latest firmware (9116 chipset).  Then we attached a LSI
>> DE2660 JBOD array to it, with 60 hard drives.
>
> TTBOMK LSI never made a 60 drive JBOD chassis.  Is this actually 3x 24
> bay JBOD chassis daisy chained?  Did you buy them on Ebay or are these
> simply being redeployed?  All LSI drive chassis, both JBOD and SAN/DAS
> RAID, have been discontinued for quite a while.

Technically it is a E2660 Engenio "expansion" Array.  These arrays are 
indeed 60 disks (in 4RU), they are front loading with 5 12-disk "trays" 
connected to a common backplane.  NetApp recently acquired the LSI 
Engenio division, so I guess really it isn't LSI anymore, but now 
NetApp.  It was purchased like 4 months ago right before NetApp took 
over the group.

> First remove and re-seat all SFF8088 cables.  Then replace them one by
> one until the errors/problems are eliminated.  If not test each chassis
> expander module individually with only one in the chassis.  Test it in
> both module bays.  Basic process of elimination stuff.

I've not tried it with only one expander in the chassis, good idea.

> Given you're receiving errors on multiple drives I'd say you have a bad:
>
> 1.  Cable
> 2.  Backplane
> 3.  Expander module
> 4.  PSU

Yeah something is weird, I seem to be receiving errors on every single 
drive.  Either it's a driver issue or maybe even with the HBA, or 
something weird with the array/backplane.

Thanks for the reply!

cheers,
erich