Just a note - I've filed an RFE to get this addressed. I don't see a reason why snapshots need to be deleted during a split operation, but there could be something about WAFL that makes that harder to do than it may seem.
I'll keep this email on record and provide an update when I learn something, but it will probably be a while before I get any clear answer either way.
It's good to know the vol-move procedure is a viable workaround in some cases, but it would be nice to avoid the extra IO.
From: Chris Hague [mailto:Chris_Hague@ajg.com] Sent: Friday, September 01, 2017 11:26 AM To: Chris Hague Chris_Hague@ajg.com; Steiner, Jeffrey Jeffrey.Steiner@netapp.com; Toasters@teaparty.net Toasters@teaparty.net Subject: RE: vol clone split
For those interested; You cannot perform a vol clone split on a cloned vol with snapmirror \ snapvault etc. as it needs to delete all snaps. We resolved this by performing a vol move to another aggregate and then a move back. Luckily we had enough space for this and it was pretty quick for 5tb it took only a few hours. (CDOT handles vol moves MUCH better than 7-Mode). Every day is a school day!
From: toasters-bounces@teaparty.netmailto:toasters-bounces@teaparty.net [mailto:toasters-bounces@teaparty.net] On Behalf Of Chris Hague Sent: 30 August 2017 13:14 To: Steiner, Jeffrey <Jeffrey.Steiner@netapp.commailto:Jeffrey.Steiner@netapp.com>; <Toasters@teaparty.netmailto:Toasters@teaparty.net> <Toasters@teaparty.netmailto:Toasters@teaparty.net> Subject: RE: vol clone split
From here; https://kb.netapp.com/support/s/article/ka21A0000000eO1QAI/faq-flexclone-spl...
Are there any special considerations for using FlexClone split?
Splitting a FlexClone volume will result in all the snapshot copies on the FlexClone being deleted and will prevent any new snapshots on the FlexClone volume until the split completes. The FlexClone split operation is processed by a background scanner at a low priority and can take a considerable amount of time to complete. FlexVols with many inodes (files) will process slower than FlexVols with few inodes (files).
This is most annoying as I'm pretty sure that CDOT won't allow me to re-baseline the mirror to the same destination volume. Can anyone confirm this? As this is actually a snapvault destination, I would mean I have to create another destination volume and keep my original one simply to hold all of the backup snapshots. Effectively doubling the baseline storage for all of these volumes.
From: Steiner, Jeffrey [mailto:Jeffrey.Steiner@netapp.com] Sent: 30 August 2017 12:21 To: Chris Hague <Chris_Hague@ajg.commailto:Chris_Hague@ajg.com>; <Toasters@teaparty.netmailto:Toasters@teaparty.net> <Toasters@teaparty.netmailto:Toasters@teaparty.net> Subject: RE: vol clone split
I'd recommend opening a support case on this one. I don't see a technical reason why a split should require deleting snapshots, nor can I think of a reason why a snapmirror baseline should block a split operation. I suspect there are diag level overrides for that behavior but it would probably depend on the exact version of ONTAP. I know that's speculative, but I don't want to give bad advice that would result in a major inconvenience if the snapshots went missing.
From: toasters-bounces@teaparty.netmailto:toasters-bounces@teaparty.net [mailto:toasters-bounces@teaparty.net] On Behalf Of Chris Hague Sent: Wednesday, August 30, 2017 11:29 AM To: <Toasters@teaparty.netmailto:Toasters@teaparty.net> <Toasters@teaparty.netmailto:Toasters@teaparty.net> Subject: vol clone split
Hi Toasters,
I have a number of volumes running from a common snapshot and would like to split them out. All these volumes are snapmirrored to our DR site.
However, when I try to perform a vol clone split, it complains about an in-use snapshot. Reading further, it appears that the split will delete all snapshots, so doesn't like the snapmirror snap.
What is the best way to split these volumes? Ideally without having to re-baseline \ lose my snapmirror destination volume \ snaps.
ONTAP v9.1P2
Error below; Time Node Severity Event ------------------- ---------------- ------------- --------------------------- 8/30/2017 09:02:17 filer1 INFORMATIONAL mgmtgwd.jobmgr.jobcomplete.failure: Job "Clone Split" [id 6716] (Split vol1) completed unsuccessfully: Volume has locked snapshots (1). 8/30/2017 09:02:17 filer1 DEBUG wafl.config.req.error: Config request 'VV_CONFIG_REQ_CLONE_SPLIT_START' by WAFL for volume vol1 is not being processed because of the error: '387 - CR_VV_VOLUME_SNAPSHOTS'. 8/30/2017 09:02:17 filer1 NOTICE wafl.vv.clone.splitBusySnap: Volume 'vol1 has locked snapshots, not splitting.
KR, Chris.