topic Re: Powershell Help in ONTAP Discussions

Powershell Help

axsys — Wed, 04 Jun 2025 15:16:48 GMT

Hey Guys,

Have a powershell question, if you could help me?

I have a volume and clone volume in the same svm. the svm is in a snapmirror relationship every 15 minutes. At some point after a month or two I remove the clone, create a new one and want to get rid of the unneeded data = remove old snapshot.

situation before:

> Connect-NcController –name filer1 -Vserver svmtest

> get-ncvol | foreach-object {$ParentName=$_.Name;get-ncsnapshot $_.Name clone*}

Name Volume Vserver Created Total Cumulative Dependency

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

clone_volftest.0 volftest svmtest 3/27/2017 800.0 KB 888.0 KB

clone_volftest.1 voltest svmtest 3/27/2017 456.0 KB 1.4 MB snapmirror

clone_volftest.0 voltest svmtest 3/27/2017 84.0 KB 180.0 KB busy,vclone

I'm running this cmdlet to get rid of the obsolete snapshots:

get-ncvol | foreach-object {$ParentName=$_.Name;get-ncsnapshot $_.Name clone*} | where-object {$_.Dependency -eq $null} | remove-ncsnapshot -Confirm:0 -ErrorAction SilentlyContinue

situation after:

Name Volume Vserver Created Total Cumulative Dependency

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

clone_volftest.0 voltest svmtest 3/27/2017 84.0 KB 280.0 KB busy,vclone

Can anyone tell me why it's removing the snapshot that still has Dependency "snapmirror" in it? Dependency is not empty in this case, why is he removing that one too?

Problem is that this one is breaking my mirror and completely replicates my clone volumes which turns out to fill up my space in the DR.

Thanks,

axsys

Re: Powershell Help

JGPSHNTAP — Tue, 28 Mar 2017 10:56:18 GMT

I personally would have tackled this different.

I'm not a fan of using ; in any powershell string if I don't have to.

If you know the snapshot can be deleted based on a date, then you should be querying the name and off this date.

For example

PS C:\powershell> get-ncvol | get-ncsnapshot | ? {$_.name -like "*hourly*"} | ? {$_.created -lt (get-date).adddays(-80)} | remove-ncsnapshot -confirm:$false

I chose hourly in my example, but if you have a specific name pattern in there, put it there, and then where I have -80, just put your date target there.

Re: Powershell Help

axsys — Tue, 28 Mar 2017 11:43:45 GMT

Thanks for the answer but I don't know the date. the clone could be 2 years old or 1 week and I don't want to go and check when it was created.
What I'd like to achieve is to get rid of all clone snapshots, not snapshots in general, on the whole system that are not busy. Question stands: why is the remove-ncsnapshot removing the snapshot with "snapmirror" dependency? It should only remove the ones that are empty....

Re: Powershell Help

JGPSHNTAP — Tue, 28 Mar 2017 12:13:32 GMT

Can you do me a favor, and show me the scenario where you remove the clone and have a new clone in a snapshot list.

That will help me out

Re: Powershell Help

axsys — Tue, 28 Mar 2017 13:36:25 GMT

Name Volume Vserver Created Total Cumulative Dependency

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

clone_volftest.0 volftest svmtest 3/27/2017 800.0 KB 888.0 KB

clone_volftest.1 voltest svmtest 3/27/2017 456.0 KB 1.4 MB snapmirror

clone_volftest.0 voltest svmtest 3/27/2017 84.0 KB 180.0 KB busy,vclone

it's all there already? The one which says "snapmirror" under Dependency is not a busy clone - it's the old clone that I have offlined and removed. If I run the remove-ncsnapshot above cmdlet above it will remove that one too besides the one without an empty Dependency. Hope that makes sense?

Re: Powershell Help

JGPSHNTAP — Tue, 28 Mar 2017 13:52:35 GMT

Ok, I'm not trying to be difficult here.

Are you trying to remove this one

clone_volftest.1 voltest svmtest 3/27/2017 456.0 KB 1.4 MB snapmirror

Or not?

Run a basic query instead of using $null use ""

For example, try this

get-ncvol volname | get-ncsnapshot | ? {$_.dependency -ne ""}

Can you highlight in bold the one you want to delete that will help me

Re: Powershell Help

axsys — Tue, 28 Mar 2017 14:42:55 GMT

That's it. I only want to remove the clone snapshots that are empty in the field dependency. I query that with $null. I remember from the past trying it with "" but replaced it later with $null, can't remember why tho.

I do ask where-object {$_.Dependency -eq $null}. to me this means Dependecy has to be empty in order to remove the snapshot? or am I wrong?

Thank you!

Carlos