Replacing all disks in an Equallogic PS series SAN

I recently ran into a situation where i was maxing out the disk IO in a PS6000 SAN with 16 1TB SATA disks.

Rather than replace the whole SAN, i wanted to just replace the disks since i wasn’t maxing the network links. I got a quote from Dell for some SAS disks: *whistles* I almost had a heart attack!

So i found a post suggesting that it will take non supported disks, but wont be supported – this was fine since the unit was out of warranty anyway. So i ordered some SAS disks from a 3rd party vendor (Hitachi 600GB 15k SAS).

Now, the SAN i was working with was already in production with 1TB disks, and you cant shrink a volume…. hmmm.

Ok, no worries, i shifted all the IO of the SAN and deleted the volume. And then went to delete the RAID set before replacing the disks…… NOPE! You can’t do that, you have to reset the WHOLE array to defaults :'(

So now i was in a position that i would have to set it all up again 🙁 which would take time …. booo….

There must be a better way!!! ….. and there is!

login to the unit at the CLI (You cant do this from the GUI)

enter the command “save-config <your choice of file name>”
Connect to the unit with SCP / FTP and copy this file to your desktop

Now take some screenshots of all the settings if you want to be double safe, and then power off the array.

Replace all the disks in the array at this point. If you are trying to reuse the SATA caddies with SAS disks, you may notice the drives don’t sit flat 🙁 this is a big issue. There are 2 mounts at the end of the caddy for the SATA to SAS adapter to screw into. You will need to remove this or the SAS disk will not go back into the array. A big drill bit and a file and your set to do this. Alternatively you can order some caddies off eBay without this mount on them.

Power the array up, connect into it with a console cable. You will get a whole heap of unsupported disk warnings, just ignore those and login. The array will have already reset itself to default.

Create the group and IP again.

Once you get out of this auto installer, open your file that you SCP’d off the array and copy the commands in the file to the array. This will set it all up again. Just don’t copy any of the array, group, volume or snapshot lines. You will need to do some more thought before copying those as the array size has changed.

Once you get all the networking setup, open up the web GUI again and recreate the array and your volumes. You can also check the disks are ok.

I didn’t actually check a roll back (i didn’t have a need to) but i you put all the disks back in their correct slots and restore the config file exactly you should be ok. (the disk spot is fairly important as the array config is on both the controller and the disks)

And that should do it! I just wish i didn’t have to reset the array 🙁

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