Downgrading firmware on a NetApp SAN

If you have just reclaimed a shelf from a NetApp SAN that you would like to use with an older head, you will notice that the drives are not recognized. This is due the the fact that DataOntap upgrades the drives automatically when you plug them in to an updated shelf, but it won’t downgrade or even recognize correctly drives that come from an higher level revision.

Downgrading drives while keeping the contents is actually impossible.

Actually downgrating the firmware on NetApp SAN drives

Chances are that you don’t really need to downgrade the firmware on the drives, and you can just skip to the next section.

If you are sure you need to downgrade the drives, here are the basic steps:

  • Get a linux box, with a qlogic HBA, and cables that can attach to the shelf that has the drives to downgrade
  • Make sure only the drives that you want to downgrade are in the shelf
  • Make sure the proper disk qualification package is on the filer (if not, download the Disk Qualification Package as a zip file from: http://now.netapp.com/NOW/download/tools/diskqual/ and extract it to the /etc directory of the NetApp)
  • Download all current disk firmware from http://now.netapp.com/NOW/download/tools/diskfw/
  • Get the right firmware for your disk (the new you just downloaded, or an old one, if you need to downgrade) — the old firmware is already on the root volume of the netapp
  • Use the proper firmware upgrade tool from your manufacturer to flash the firmware from the Linux box

Wiping labels on NetApp SAN drives

If you simply can’t get the old filer head to recognize the drives that had new labels, the only viable solution to get the drives to work is to reconnect the shelf to the old filer head that was running a newer firmware.

Erasing labels on NetApp SAN drives

  • Boot into maintenance mode (CTRL+C at boot and then Option 5)
  • list the drives:
  • erase the labels: where 4.23 is the drive number to wipe
  • exit maintenance mode:

Chances are that this will still not allow the older filer to see the drives properly. The next step always works: zero the drives.

Zeroing spares on NetApp filer

  • Boot into maintenance mode (CTRL+C at boot and then Option 5)
  • list the drives:
  • force the drives to become spares: where 4.23 is the drive number
  • exit maintenance mode and boot:
  • zero the spare drives:
  • remove the shelf or the drives from the new filer, and you can now put them back into the old filer, as they will be recognized just fine.

For more information about our SAN support, look at NetApp SAN.