Re-using NetApp ONTAP 8 drives with a ONTAP 7.X system

My company recently had a client who was re-using drives from an ONTAP 8.0.X system for a ONTAP 7.X system. Here are a few notes from that experience.

This is not as easy as it sounds. And that IS A GOOD THING. I love how NetApp systems can read any disk (a high level of backward and forward compatibility), yet draw a clear line in the sand of what they will and will not reformat. The ONTAP 7.X system will discover the 8.X disk, which uses a RAID format that 7.X is unfamiliar with, but it is smart enough to say “Look my friend, I know this is a NetApp disk, and yes I even know it’s a newer disk, but I’m not going to let you shoot yourself in the foot and reformat it. I (Mr. NetApp) will only allow you to do what I have been qualified and designed to do.

There are many times when IT engineer would like systems to be less restrictive and just blast things away. But having systems be intelligent enough to only do what they were designed to do is never a dangerous thing. Positive acknowledgement is a wonderful thing!

With the ONTAP behavior being the way it is, yes it is more work, however it is far safer and ensures that engineers know what they are doing and are fully aware of the consequences. Whatever data was on the disk, it will be absolutely 100% unrecoverable once it is consumed back into a ONTAP 7.X system.

One of the first clues that you will see when ONTAP 7.X discovers the 8.X disk is a message with the string “unsupported label version”. That the first clue. Surfing the web will reveal some instructions on fixing this problem (as shown below). However, don’t bother in this case as the following procedure will not work if the disk in from a later ONTAP release:

  1. Lookup the disks which show the error,
  2. Reboot the filer and press ctrlC,
  3. From the 1-5 menu, choose option 5 to boot into maintenance mode
  4. Clear the label on those disks by typing: label wipe <disk_ID>

Rebooting the NetApp filer with 7.X, and performing the above procedure, will not work. The error message that you will discover is something like the following (SN blanked out to protect the customer):

Thu Jun  2 04:07:27 GMT [raid.config.disk.bad.label.version:error]: Disk 0d.112 Shelf 7 Bay 0 [NETAPP   X292_HVIPC560F15 NA00] S/N [XXXXXXXX] has an unsupported label version.

The following is from (http://communities.netapp.com/thread/12897?tstart=2), and is a perfect summary of the situation:

Before we move disks from a 7.3 system (even if spares) to a 7.2 system (and similarly from 8.0 to 7.3) is to download and revert_to the older release prior to moving the shelf so the RAID is compatibile.  Newer ONTAP has a newer label and it isn’t understood from 7.3 to 7.2 even for just spare disks.  If you can’t do revert_to on the system that owned the disks, we use a test/dev/lab system to do the revert.  The other option is to upgrade the 3140 to 7.3 to work with this shelf.

So, the only way I know to make it work 1) put the shelf on a 7.3 system that you can revert_to 7.2    2) upgrade the 3140 to 7.3.  If you decide to stay on 7.2 and remove the shelf to do a revert, remember that there is no hot shelf removal, so you need to halt the 3140 prior to removing the shelf.

In summary –

  1. Put your 7.X disk onto a 8.X system
  2. Downgrade (revert_to) the entire NetApp system from ONTAP 8.X to 7.X, and the disks will be reverted with it.

If you plan on reverting disks often, it might be viable to keep an inexpensive (and small!) NetApp filer around that can quickly upgrade and revert ONTAP versions. Looks like I’ll be trying to provision such a resource myself.

Good luck with it.

One thought on “Re-using NetApp ONTAP 8 drives with a ONTAP 7.X system

  1. I had the same problem when swapping disks between an Ontap 8.0.1P5 and an Ontap 8.3.6P4 System. If you do not need the data on the disks you need to move them back to the Ontap 8 system (can be done one disk at a time) and follow this procedure:

    On the Ontap 7 system:
    options disk.auto_assign off
    options autosupport.enable off

    use sysconfig -r to find the unusable disk(s).

    disk assign DISKNAME -s unowned
    priv set advanced
    blink_on DISKNAME

    Take out the blinking disk with the unusable label

    On the Ontap 8 system:

    options disk.auto_assign off
    options autosupport.enable off

    Put the disk with the unusable label and into a tray on the Ontap 8 system

    disk show -n

    disk assign DISKNAME -o FILERNAME
    aggr destroy aggr_whatever_if_any
    disk zero spares
    disk assign DISKNAME -s unowned
    priv set advanced
    blink_on DISKNAME

    Now remove the blinking disk and place it in the Ontap 7 system:

    disk show -n
    disk assign DISKNAME -o FILERNAME

    You should now see a usable zeroed spare.

    You can repeat this process for all the disks using one or more of the hotspares on the Ontap 8 filer or move an entire tray after unowning the disks. Just make sure you don’t have any online aggregates on there, cause your filer will panic even if there is no volume whatsoever on the aggregate. Be sure to check and double check (or have someone else double check).

    After all the disks are done, you may want to switch the options autosupport,enable and disk.auto_assign back to on again on both filers.

    Use this workaround at your own risk, and please don’t do it while tired or on a time limit. This will procedure may take a while, but will save you the hassle, downtime and snaphot loss that comes with downgrading a filer from Ontap 8 to Ontap 7

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