Snapvault source retention confusion

[pflum]

So, I just setup snapvault for the first time, and I was under the seemingly incorrect impression that once a scheduled snapvault copy occured the source snapshot would be deleted.  For example, on the source filer I have a regular snapshot schedule with 6 hourly & 2 nightly, but on the vault destination I'd like to keep 7 nightly's & 12 weekly's.  When I look at the .snapshot dir & 'snap list' of the source filer I see the nightly & hourly, but also the snapvault nightly & weekly's and that's confusing me.  Are the sv nightly's supposed to take the place of the normal snapshot nightly's?  I don't want to retain that many snapshots on the source, can I set the 'snapvault snap sched' on the source differently than the dest?  I get that you can vault from multiple sources to one dest, so the snapshotting will be differant than a normal snapmirror, but there's clearly something I'm missing here, cause I wasn't anticipating the source retaining anything...

Source:

source_filer> snap list vol1a

Volume vol1a

working...

  %/used       %/total  date          name

----------  ----------  ------------  --------

  1% ( 1%)    0% ( 0%)  May 22 12:00  hourly.0       

  4% ( 2%)    1% ( 1%)  May 22 08:00  hourly.1       

  5% ( 2%)    2% ( 1%)  May 22 00:00  nightly.0      

  6% ( 1%)    2% ( 0%)  May 21 22:00  sv_nightly.0   (snapvault,acs)

  7% ( 1%)    3% ( 1%)  May 21 20:00  hourly.2       

  7% ( 0%)    3% ( 0%)  May 21 16:00  hourly.3       

  7% ( 0%)    3% ( 0%)  May 21 12:00  hourly.4       

  7% ( 0%)    3% ( 0%)  May 21 08:00  hourly.5       

10% ( 4%)    4% ( 1%)  May 21 00:00  nightly.1      

10% ( 0%)    4% ( 0%)  May 20 22:00  sv_nightly.1   

11% ( 1%)    4% ( 0%)  May 19 22:00  sv_nightly.2   

14% ( 4%)    6% ( 2%)  May 18 22:00  sv_nightly.3   

18% ( 5%)    8% ( 2%)  May 15 23:00  sv_weekly.0    (acs)

18% ( 0%)    8% ( 0%)  May 15 22:00  sv_nightly.4   

18% ( 0%)    8% ( 0%)  May 14 22:00  sv_nightly.5   

19% ( 1%)    8% ( 0%)  May 13 22:00  sv_nightly.6   

25% (10%)   12% ( 4%)  May 08 23:00  sv_weekly.1    

32% (12%)   17% ( 5%)  May 01 23:00  sv_weekly.2    

source_filer> snap sched vol1a

Volume vol1a: 0 2 6@8,12,16,20

source_filer> snapvault snap sched vol1a

create vol1a sv_nightly 7@mon-fri@22

create vol1a sv_weekly 12@fri@23

Destination:

dest_vault> snap list vol1a

Volume vol1a

working...

  %/used       %/total  date          name

----------  ----------  ------------  --------

  2% ( 2%)    1% ( 1%)  May 22 02:29  sv_nightly.0   

  9% ( 8%)    5% ( 4%)  May 22 01:37  dest_vault(0536960232)_vol1a-base.0 (busy,snapvault)

12% ( 3%)    6% ( 1%)  May 21 01:16  sv_nightly.1   

12% ( 1%)    6% ( 0%)  May 19 22:52  sv_nightly.2   

12% ( 0%)    6% ( 0%)  May 19 02:57  sv_nightly.3   

13% ( 0%)    6% ( 0%)  May 15 23:18  sv_weekly.0    

13% ( 0%)    6% ( 0%)  May 15 22:48  sv_nightly.4   

13% ( 0%)    6% ( 0%)  May 14 23:27  sv_nightly.5   

13% ( 0%)    7% ( 0%)  May 14 01:15  sv_nightly.6   

13% ( 0%)    7% ( 0%)  May 09 01:34  sv_weekly.1    

16% ( 4%)    9% ( 2%)  May 01 23:51  sv_weekly.2    

dest_vault> snap sched vol1a

Volume vol1a: 0 0 0

dest_vault> snapvault snap sched vol1a

xfer   vol1a sv_nightly 7@mon-fri@22 preserve=default,warn=0

xfer   vol1a sv_weekly 12@fri@23 preserve=default,warn=0

[YIshikawa]

You can restore files from SnapVault primary snapshots,so you can disable 'snap sched' scheduling if you would like.
You can also set "snapvault snap sched" differently on primary and secondary. On the primary filer, set number and schedule of snapshots kept on primary. On the secondary filer, set number of backup copies(snapshots) and transfer schedule.

[JGPSHNTAP]

Why are you creating snapvault snapshots on the primary.

I'm not exactly sure you are doing this properly....

What is controller the snapvault transfer?

[pflum]

Thank you for the replies.  As to why, we had a consultant install and config the filers as none of us had done it.  Now obvioulsy as we learn more, I'm second guessing their setup.  The overview they gave us was that a snapshot needed to be created on the source ("create vol1a sv_nightly 7@mon-fri@22") and a transfer setup on the destination ("xfer   vol1a sv_nightly 7@mon-fri@22 preserve=default,warn=0").  It seemed reasonable at the time, create a snapshot on the source, transfer the delta over to the destination, but then I assumed the source snapshot would be deleted, which it isn't.  Are you saying the create on the source is unnecessary, and that we only need to schedule the transfer on the secondary/destination?

[JGPSHNTAP · Accepted solution]

Ok, unless i'm completely off base, which I don't think i am b/c i know 7-mode snapvault pretty well, i believe your consultant set the environment up wrong.

There is no need to create snapvault sched's on the primary.  This is a complete waste.  The way snapvault works is you create an xfer snapvault schedule and once it's done doing the snapvault update it then creates the snapvault snapshot.

I have absolutely no idea what your consultant did because to me that doesn't make sense.  He's not using a named snapshot from what i can see.

Are you mirroring that source volume as well?

Also, make sure your dst vol has no snap sched on it.

[pflum]

Xfer only is sounding more in line with what I was expecting.  We are not snapmirroring the source, and we do have snapshots turned off for the dest vol's.  Thank you!

[aborzenkov]

---

i believe your consultant set the environment up wrong.

There is no need to create snapvault sched's on the primary.  

---

That's not what documentation says and not how I was told SV works. You must create snapshots on primary, because they are what secondary transfers. Schedules on secondary only say when and which snapshots to transfer - they do not cause snapshots themselves be created on primary.

Now you of course can have different retention policy on primary and secondary, but you still need at least one snapshot of each kind (hourly, nightly, weekly etc) that you want to transfer. I'm not aware of option to "create snapshot, transfer, delete snapshot".

[JGPSHNTAP]

^^

Only if you are using a named snapshot, which I might have mistated because this isn't a VSM target so you aren't using the VSM base snapshot.  If you are using the VSM base snapshot then you dont' need source snapshots.. so I'm glad you corrected me..