Slow RS6000

[normntwrk]

We purchased a refurb IBM,7026-B80 with an external 2 TB disk Array (which I configured into 2 1 TB RAID 5 arrays). It has 4 Gigs of RAM and 2 Procs.

This machine is so slow it isn't funny. Just copying a 2 Gig file from one RAID array to another or the same file from a Directly attached disk to another directly attached disk takes around 3 min 45 sec. Creating a file system takes a lot longer than I have ever seen on another machine. Running Topas while this is going on shows the CPU in a 50 % wait state

errpt comes back clean

Any ideas what I can look at ?

Norm

 

[psi07004]

These older systems typically have ultra scsi disks with a (narrow) bandwidth of 20MB/sec. Give this, if the system was doing nothing else, under perfect conditions it would tape about 2 minutes for the copy. Now add in the overhead of RAID, disk seek time and the like, and your time to copy would seem typical, and not unreasonable.

You don't say, but I am guessing you have a single scsi RAID adapter sharing the load for the two arrays.

Of couse this is a guess without knowing your configuration. If you want to post the rest of the info for the processor type, raid controller, external array, and disk type that would help.

 

[normntwrk]

That is correct in there is only one raid adapter

Some of the disk info

hdisk0 10-88-00-8,0 16 Bit LVD SCSI Disk Drive
hdisk1 10-88-00-9,0 16 Bit LVD SCSI Disk Drive
hdisk2 10-88-00-10,0 16 Bit LVD SCSI Disk Drive
hdisk3 10-88-00-11,0 16 Bit LVD SCSI Disk Drive

pdisk6 10-70-140A-01-P SSA160 Physical Disk Drive
pdisk5 10-70-140A-02-P SSA160 Physical Disk Drive
pdisk3 10-70-140A-03-P SSA160 Physical Disk

SCSI controller...............
scsi2 20-58 Wide/Ultra-2 SCSI I/O Controller

DUAL CHANNEL PCI TO ULTRA2 SCSI ADAPTER:
Part Number.................03N3606
--------------------------------------------
SSA Raid adapter
ssa0 10-70 IBM SSA 160 SerialRAID Adapter
(14109100)

Part Number................. 09L5695
---------------------------
Not sure how to get the Processor type

I just noticed a power supply issue after reboot that I didn't see before ....wonder if that could have anything to do with the issue ??

 

[psi07004]

I see you have an SSA adapter, and your RAID arrays on that. One of the first things to check is the SSA cabling. You mention you recently purchased this used system. Who did the SSA fiber cabling. If done wrong it could be an issue. There is an entire manual on SSA cabling. You could check this with SMIT, Problem Determination, Hardware Diagnostics, Current Shell, Task Selection, SSA Service Aids. Run the two verification tasks and the link speed and link verification to see if it all looks good. What color are the fiber cables, and how many do you have?

I can't tell from what you supplied, but I am guessing that you created two ranks on the same link. If so, this could be the bottleneck. If all else looks good you could move one of them to the second link.

How many physical disks are in each raid array?

Post again with the results of the above.

 

[normntwrk]

The cables are Blue, we cabled them up the way the vendor told us to

Link verification came back good
Link speed came back at 40 for all devices

8 disks in one array
7 disk in the other
1 hot spare

I was going to create one array but I read somewhere that 4.3.3 would only support 1 TB per array