Data ONTAP Discussions

Using Protection Manager for QTree SnapVault

Hi everybody

I have a question about the following scenario

  • Qtrees are location in different volumes with in the same aggregate on primary storage controller
  • On Seconday I just have created a big volumes which should act a SnapVault destination

Question is now how I have to configure this within Protection Manager?

  • Create dataset where the different QTrees are added from the primnary
  • Use the default ProtectionManager Backup policy and select the SnapVault destination volume from the secondary

Is this the correct way to get it done or are there some others things which I should take care of?

Thanks a lot



Using Protection Manager for QTree SnapVault

Hi Thorsten

When you use Protection manager to do the work, it is recommended to let PM do the provisioning of the destination volume(s).

But... You have 2 options...

1. create the snapvault relationship on the CLI and then import it. This will give you the "full control" over the destination volume to be used.

2. Let Protection Manager provision the destination volume(s). Here you should make a copy of the backup policy you want to work with and then relate it to the provisioning policy and the schedule you want to use.

Hope this helps,


Using Protection Manager for QTree SnapVault

There's a third approach to Peter's two.

  Create an empty dataset and apply your backup protection policy.

  Add your large secondary volume to the Backup node.

  Add your primary qtrees to the Primary node.

I think this is pretty much what you suggested. You have to do it in this order (backup volume first) because otherwise, when you add the primary qtrees, we'll immediately try to create a new secondary volume.

You need to ensure the option "dpMaxFanInRatio" is increased from it's default value of 1. This controls how many source volumes we allow to be backed up to a single secondary volume. You change it from the CLI:

  $ dfm option set dpMaxFanInRatio=4 (or whatever value you need, 4 to 8 are good values.)

Using Protection Manager for QTree SnapVault


Thanks for your comments.

I used nr 1 which is working fine now.

Also tried now to add an additional QTree to the Physical Resoures list using ProtectionManager. But I got a message that I have to create a new flx vol with the size of the source vol + 40GB. That's really funny. So to add new source qtrees I do it on the cli with snapvault -s source filer:qtree destination filer:qtree. After some time it's listed in ProtectionManager as external relationship and can then be imported. A little complicated but it works.


Thanks as well. Will try our way, too. Does I got you right that it's a must  to change the "dpMaxFanInRatio" value? Take in mind that I want to have source qtrees from different vols/aggres and maybe filers snapvaulted to a single destiantion volume on our backup filer.



Re: Using Protection Manager for QTree SnapVault

Hi Thirsten

the maxfaninratio is controlling the behavior of Protection Manager. From the message you mentioned I assume it is set to 1 right now. Just take smoots advice and put it to a number you need it.

If you set it to 4, this means that Protection Manager will allow you to add up to 4 qtrees to be snapvaulted into one destination volume.


Using Protection Manager for QTree SnapVault

Peter, you're close but not exactly correct. Setting dpMaxFanInRatio to 4 means data from four source volumes can be backed up to a single secondary volume. The number of qtrees is a separate issue.

There is a second setting, dpMaxSvRelsPerSecondaryVol, which controls how many qtrees, from however many primary volumes, we'll back up to a single secondary volume (there are corresponding dpMaxQsmRelsPerSecondaryVol and dpOSSVDirMaxSvRelsPerSecondaryVol). The default values for these are in the 50-100 range but I don't recall the actual values right now.

If you exceed either of these limits, Protection Manager will attempt to select or provision a new secondary volume.

Using Protection Manager for QTree SnapVault

Hi pete,

     The default value for all the MaxRel options is 50.Also there are other situation when we create a new volume.

For others adding what I know based on my experience.

So even if you have a Fan-In ration of 4 it happens only when the following conditions are satisfied

  • Maxrelspersecondaryvolume is not exceeded.
    • So in you primary volume you have 51 qtrees then PM will create 51 qtree snapvault relation which will exceed the max rels, so two destination volume will be created.
  • PlatformDedupeLimit is not exceeded.
    • Example, you alread have 2 destination volume becaue of the above scenario, now you add another volume to the same dataset primary, then PM will try to increase the size of the second secondary volume while doing that if  it will exceed the max volume limit for dedupe enabled volume for a given platform, again it will create a 3rd secondary volume and not use the existing 2nd volume.
  • Volume Language  is same for the existing destination volume and the new primary volumes
    • If the volume language of the 3rd primary volume is different from the volume language of the other two primary volume, then PM will create a 4th Secondary volume and not use the same volume.

By this you will end up with 4 secondary volume to backup qtree coming from 4 primary volumes inspite of fan-in being 4.

Hope this helps.



Using Protection Manager for QTree SnapVault

Hi All,

I'm having an issue with my OSSV setup with protection manager. I need to setup up 5 OSSV clients into one dataset but create different volumes for each OSSV. Currently its provisoning 1 Volume per dataset and adding qtrees to this volume for each client.

my FAN-IN ratio is set to 1, but I've read this options doesn't apply to OSSV. The other options mentioned above dpMaxSvRelsPerSecondaryVol,  dpMaxQsmRelsPerSecondaryVol, dpOSSVDirMaxSvRelsPerSecondaryVol I can't fine inf DFM.

My DFM version 5.0.

Thanks in advance.


Using Protection Manager for QTree SnapVault

If you want to control one volume per OSSV host. Then you should add one OSSV host at a time to the dataset and set the dpOSSVDirMaxSvRelsPerSecondaryVol to nubmer of drives or mount points that you are backing up.

so the example, if you have 5 ossv host with each one having 1 2 3 4 and 5 drives.

  1. add ossv host1 and set the dpOSSVDirMaxSvRelsPerSecondaryVol=1 then PM will provision 1 secondary volume for this ossv host.
  2. add ossv host which has 2 drives and set the dpOSSVDirMaxSvRelsPerSecondaryVol=2 then PM will provision 1 secondary volume for this ossv host.

And so on.



Using Protection Manager for QTree SnapVault

Hi Adai,

Thanks for the fast reply. where do I set the  dpOSSVDirMaxSvRelsPerSecondaryVol option. I've searched for the command in DFM but can't find any reference and also on the NOW site.