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Broken disk on a KZPAC RAID array

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F. Javier Cobas
Occasional Advisor

Broken disk on a KZPAC RAID array

I have a KZPAC RAID Array 230/Plus (3 channel,
7 target, 4 MB. cache, i think.) installed on
an ES40 Alphaserver.

The other day one of the physical disks that form the logical drive "re4" has broken.

I have the following diagram for the logical distribution of the three "re4" physical disks from the previous sysadmin, but i am not able to tell for sure which one is which physical
disk in the machine:

0 1 2 <== Controler
------------------------- number
| | | |
0 | | | |
| | | |
1 | | | |
| | | |
2 | | | |
| | | |
3 | | | |
| | | |
4 | | | H.Spa.|
| | | |
5 |re4-1 |re4-2 | re4-3 |

On the front side of the machine i can see two disk rows,each one composed of 6 physical disks.

On the rear side there is another 6 physical disk row. (The first disk, on the right side, must be the broken one, as it has the ambar led light on).

Individual disks are the following model:

DS-RZ1DA-VW (9.1 GB., 7200 rpm, Fast SCSI-2 )

I would like to ask for some new disks to replace the broken one and also to have some in store to anticipate future problems.

1) Where are located the "re4" disks and the "Hot Spare" physically on my ES40 ?.

2) Which "new" disk models may be compatible? (HP and/or others).
(I mean: "New" (not refurbished) model disks that i can buy nowadays. I have the table of disk supported from the KZPAC StorageWorks Release Notes, but i guess all of them are obsoleted by now)

3) Do i have to buy 9.1 GB. disks or may i buy higher capacity disks?

4) I have read somewhere this model can have up to 21 disks, max. 8 disks on each controller. However, it seems there is no physical room for new disks there.
Can I add more controllers than i have now and/or more disks ?.

Pieter 't Hart
Honored Contributor

Re: Broken disk on a KZPAC RAID array

Your KZPCA-controller probably has 4 ports, wich can be connectd to 4 BAxxx disk enclosures (you have 3 installed) with each max 7 disks + 1 power supply wich totals to 4 x 7 = 28 possible disks .
however it looks like you have 3 x 6 disks + 2 power supplies per disk enclosure.

An ES45 has plenty of PCI-slots to add controlers depending on the model, beware some slots may be 33MHZ and other 66MHZ.

To locate individual disk I only know the way to
- bring the system down to the boot prompt
- "show config" to determine the name of the raid controler (eg pza0)
- "run bios pza0" to go into the configuration program for the controller.

When working on a raidset or on a individual disk the respective disk LED's will light up.

It might allso be possible with SWCC (storageworks command console), but I could not make it work on our configuration.
F. Javier Cobas
Occasional Advisor

Re: Broken disk on a KZPAC RAID array

Thank you for your reply, Pieter.

From the boot prompt yesterday, i was able to verify the KZPAC model is "Mylex DAC960".
I am checking your suggestions next time i am able to reboot the machine.

Actually it is an Alphaserver ES40 (not ES45) in a pedestal configuration.
It seems that there is no physical room left for more than the current 18 disks.
But perhaps changing it to Rackmount it could be expanded.

Also, from the ES40 "golden-egg" i can see it should be possible to connect a RA8000 external RAID, by installing another Mylex, ("KZPBA").
Anyone here has any experience with it? How does it work ?.

From several web pages i have learned the disk should still be available from HP, as a new disk with the same P/N. Is there any problem in having different FW level disks in the same raid ?.

I am still curious ... Can I use bigger disks, by redefining some of the logical arrays with the RCU disquette ?.
Or .. Can I replace the broken disk with another one with bigger capacity ?, asuming that case that perhaps it will only use part of the disk.

Thank you,
Rob Leadbeater
Honored Contributor

Re: Broken disk on a KZPAC RAID array

Hi Javier,

1. Identifying which disks are part of which logical drives, can be difficult with the KZPAC (aka SWXCR) controllers. You should be able to do something with the SWCC software from the OS, however as Pieter mentioned, getting it working can be tricky.

What you will probably have to do is to get into the BIOS of the Mylex card, which you normally have to run from floppy. (something like RA200RCU).

2. I don't believe there are any "new" SBB style disks available anymore.

3. A replacement drive can be higher capacity, however bear in mind that the KZPAC controllers have a limit of a 32GB logical disk, which limits things significantly...

4. If you need expansion I would get hold of a KZPDC card which is a SmartArray controller for AlphaServers. (assuming that you're using a supported OS).


You would then be able to hook up some standard disks, in a modern disk enclosure, such as an MSA30.


Hope this helps,


Hein van den Heuvel
Honored Contributor

Re: Broken disk on a KZPAC RAID array

One 'trick' I tend to use before pulling disks, to make absolutely sure what-is-what is to just make a selected disk busy and look at which busy light(s) come on.

dd if=/dev/re0 of=/dev/null

look, mark down and next...

dd if=/dev/re1 of=/dev/null

skip broken disk.
(Is it not flashing orange anyway?)