Hard drive compatibility for POWER6 p520

Hi, I have recently inherited an old p520 from work running AIX 6.1, based on the POWER6 CPU. I'm planning to play around with it and use it to learn the system, so this is a purely personal project. The machine is not under a support contract any more.

I am looking to replace one of the disks which might be failing. It's not the OS disk, and has nothing important on it. It works fine right now but a few errors were logged before I got it. I looked on eBay and elsewhere for a cheap replacement disk and there are many such items available. I was told that it needs to have the correct IBM firmware and formatted with 512 byte sectors. I found a couple of disks which are 146.8 GB, 15k RPM SAS with an IBM caddy (used but working, pulled from a server) and has 512 byte sectors, but listed for "Power Systems AIX/Linux". I believe "Power Systems" refers to newer CPUs like POWER7+, while my machine is a pSeries model.

My question is: can I use this disk on my POWER6 system? Is the newer firmware backward compatible? I'm an AIX newbie BTW so please be patient :slight_smile:

Also generally any tips for spare parts/future replacements if anyone else also has such old machines to play with?

You need to look at the host controller, host adapter, or host bus adapter (HBA) and HD support (kernel) before looking at disks, in my view. First, get an understanding of your system hardware / controllers.

What is the host adapter on your motherboard, exactly?

REF: Host adapter - Wikipedia

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The answer to my question to you above might be in this document:

IBM Power 520 Technical Overview - IBM Redbooks

http://www.redbooks.ibm.com/redpapers/pdfs/redp4403.pdf

Also attached:

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Thanks for the documentation links! I'll find out and post back.

I've successfully transplanted an IBM xSeries drive to a P520:
Source drive was a 146G FRU 39R7342.

AIX sees it as:

Manufacturer................IBM-ESXS
          Machine Type and Model......ST3146755SS
          FRU Number..................39R7354
          ROS Level and ID............42413333
          Serial Number...............3LN0H48J
          EC Level....................H17925D
          Part Number.................26K5525
          Device Specific.(Z0)........000005129F00100A
          Device Specific.(Z1)........1130BA33
          Device Specific.(Z2)........1000
          Device Specific.(Z3)........07028
          Device Specific.(Z4)........0001
          Device Specific.(Z5)........22
          Device Specific.(Z6)........H17925D
          Hardware Location Code......U789C.001.DQD7500-P2-D5

I had an extra 520 sitting about with no drives. It was going in the junk heap so I thought 'why not'. Don't recall how long I ran it, but it was non-productive use. I recall getting AIX to install was a bit of a problem. I swapped in a good Power drive that we yet to have crushed to run AIX from, then I could create a vg/lv/fs on the transplanted drive. I would not TRUST any data on it, but know that it is possible!
What you will want to watch out for is the SAS type, the P520 using 3g SAS, but if you have an IO drawer its not uncommon to have SCSI drives for the expansion. Page 15 of the redbook Neo posted above have the feature codes (yes, I still have some p520's in productive use) that are authorized.

I no longer have that system running and it went to the recycle some years ago. I was excited at the time I had to email my other AIX team member for the 'check this out' factor. That's how I know all the gory details of the transplant! Oh, this was in a 8203 frame by the way.

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Thanks this is very useful. Yes this is for personal use only. There will be no data on it.

One more question, perhaps slightly off topic: is it possible to use non-IBM disks on this machine? As an experiment, I am planning to try out a SAS drive on an empty caddy that I have to see what happens. Is this going to fail completely? Thanks!

SAS is generally SAS. So I'd say you have a really good chance that you can get a filesystem on your non-ibm drives. Just not AIX Boot.

What will come back and bite you is the firmware of the drive.

So as I said above, I couldn't install AIX directly to that drive. There's check's in AIX that prevent such things. After all, IBM wants to make sure you use their approved drives. Partly because you pay IBM, but also they can guarantee performance, features, specs, etc. Don't get me wrong, I love open systems and open source... But when it comes to my Big Iron, mission critical stuff, I want to know the vendor has my back. Down side is when you want to take such a system home, you still need to play by those rules.

AIX Diagnostic was able to see the drive and all that other info.
I had to find a real pSeries drive to install AIX from and boot from. I never did try to bring it in to the rootvg as a mirror and then reduce it to just that transplanted hdisk.

Good luck and I'd be interested to know your results.

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Once again, many thanks! This sort of information is very hard to find on the net! I'll keep posting updates as my project progresses.

Just wondering, any luck with other drives in your p520? Morbid minds want to know :smiley:

Thanks for the interest :slight_smile: I managed to score a couple of IBM power system drives on ebay and they seem to work just fine! I am only using them for data storage at the moment, no rootvg on them yet. Haven't gotten to trying out a third party drive yet.

I've disconnected them for the moment and currently keeping them as backup in case the current rootvg drive fails.

Sometimes can find some nice stuff on ebay. Good luck with your endeavors!

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you should be able to use any seagate or hitachi SAS drive up to 146GB (as IBM does not produce harddrives any more, they usually use seagates), potentially as well bigger ones but in my experience the compability issues are much higher the bigger the disks are.
Ideally - if you have access to a working AIX box - initialize the disk on a running AIX system before you plug it into the other box.

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