Need help expanding a SSA drive array

[daneicher]

For the purpose of this document I am referencing IBM REDBOOK SG24-4599

We have an SSA cabinet 7133-020 on a 7026-H50, running AIX 4.3.2.0.

We purchased this unit with 4 drives – RAID 5 one hot spare.

I have purchased four additional drives, what I would like to do, is add these 4 drives to the cabinet and expand (if possible) the current volume group.

My first task involves how to hook up the hardware.

We are currently configured like the system on PG40.

Should we reconfigure the system like PG43 – one loop –or-
Like PG 44 – two loops balanced.

-or-

Since I have two controller cards, should I be using the other card?

As the example on PG52?

Note: All disk are of the 9.2GB capacity.

# lscfg -vl ssa*
DEVICE LOCATION DESCRIPTION

ssa1 30-78 IBM SSA Enhanced RAID Adapter
(14104500)

Part Number.................025L5814
FRU Number..................025L5814
Serial Number...............C9481175
EC Level....................0000F23655
Manufacturer................IBM053
ROS Level and ID............6601
Loadable Microcode Level....04
Device Driver Level.........00
Displayable Message.........SSA-ADAPTER
Device Specific.(Z0)........DRAM=032
Device Specific.(Z1)........CACHE=0
Device Specific.(Z2)........00000020354e2b0c
Device Specific.(YL)........P2-I9

ssa0 20-58 IBM SSA Enhanced RAID Adapter
(14104500)

Part Number.................025L5814
FRU Number..................025L5814
Serial Number...............C9481266
EC Level....................0000F23655
Manufacturer................IBM053
ROS Level and ID............6601
Loadable Microcode Level....04
Device Driver Level.........00
Displayable Message.........SSA-ADAPTER
Device Specific.(Z0)........DRAM=032
Device Specific.(Z1)........CACHE=0
Device Specific.(Z2)........00000020354e2b0a
Device Specific.(YL)........P2-I1

# lslpp -h devices.ssa.*
Fileset Level Action Status Date Time
----------------------------------------------------------------------------
Path: /usr/lib/objrepos
devices.ssa.IBM_raid.rte
4.3.2.1 COMMIT COMPLETE 05/04/99 23:29:26

devices.ssa.disk.rte
4.3.2.1 COMMIT COMPLETE 05/04/99 23:29:20

Path: /etc/objrepos
devices.ssa.IBM_raid.rte
4.3.2.1 COMMIT COMPLETE 05/04/99 23:29:28

devices.ssa.disk.rte
4.3.2.1 COMMIT COMPLETE 05/04/99 23:29:22
#
Thanks for any advice,
Dan

 

[bjverzal]

I would recommend keeping the new drives on the existing loop and save the back 8-bays for the second loop.

Create a second RAID array and then use "extendvg" to add the new "hdisk" to the volume group. Pretty simple.

Unless your system is one of thousands of I/O's per second, I don't think you'll see much benefit from the additional adapter.

BV