eServer p520 - add disks for mirror 2

[mradmin]

Hi,
We have a p520 (AIX5.2) system that currently has 2 independent 36GB disks. I want to add disk space and setup disk mirroring for redundancy. So, 1) is disk mirroring the same as "RAID1"? ibm sales says I need to add 2 drives (min.) and a "RAID enablement card" to do this. So, 2) does this sound right? [the drives are reasonable, but the card is a surprising $2175.00 (USD)].
ibm also considers this a "customer install". Apart from the obvious of backup everything twice, are there any serious "gotcha's" lurking behind those covers?
Thanks for any help and insight,

---Will

 

[DukeSSD]

1) In basic terms yes. RAID1 is disk mirroring, but you don't NEED to mirror at the disk level.
2) You don't NEED the RAID card, AIX can mirror, not at a disk level but you can achieve the same redundancy by mirroring volume groups and logical volumes. It depends on how familliar you are with LVM and whether you just want to use a management tool - smitty pdam - and a RAID card to disk mirror or you want to do it via AIX, in which case there are a few things that can catch you out.

Almost every part of the 520 is "customer install" but there are instructions and videos on Info Center:

http://publib.boulder.ibm.com/infocenter/eserver/v1r3s/index.jsp?topic=/iphaj/selectcifcio.htm

 

[p5wizard]

I second DukeSDD.

You might want to invest in an additional SCSI adapter though, and split the SCSI backplane. I believe default is that both halves of the SCSI backplane are connected to the same SCSI adapter.

Might also be that the RAID enablement card that IBM sales are talking about is the whole deal: SCSI adapter, split SCSI backplane enablement, cables, ... That I don't know. Get your IBM sales rep to explain what they mean.


HTH,

p5wizard

 

[DukeSSD]

Knowing IBM sales, and from what I know of the 520, the RAID enablement card is just a plug in card (not a pci card) that converts the onboard scsi card to support RAID and probably costs about 2k just for the card. You use the existing cable / disk backplane.
p5 wizard makes a very good point about the second adapter, good idea.