Re: Deleted files didn't increase free space

MARIALIZ777 · ‎2012-10-25

Hello,

We are using NetApp FAS2020 storage system.

We use VMware in local server disks to run CentOS5.6 server.

We have mounted FAS2020 by NFS to /mnt/storage/ directory.

In /mnt/storage/mysq_backups/ we keep .gz mysql db's backups.

Before deleting backups it was 85G space left in storage (using df -h command) we have deleted 9G of mysql backups and after running df -h again we got same 85G.

Why space didn't increase? How can we get free space?

du -sh /mnt/storage/mysql_backups shows me 27G, it was 36G before delete.

So FAS2020 can't recalculate free space or what?

What are the options?

Restart server?
Restart server+FAS2020?

It would be better find solution without restart

Thanks.

scottgelb · ‎2012-10-25

Possibly a few things... there are aggr level snapshots (if looking at aggr space) disable or delete those.. or volume level snapshots... any pre-existing snaps before delete will hold blocks until the snap rolls off.

Last thing... block reclamation takes time in ONTAP and we see space come back over time... but if not seeing any usable space come back then it likely is volume snapshots which you can see with "snap list"

MARIALIZ777 · ‎2012-10-25

Hi,

I forgot to say that daily snapshots is set on FAS2020. We keep 20 weekly and 30 daily snapshots.

In Storage>Aggregates it shows:

Name Disks Status Available Space Used Space Committed (%) Total Space

aggr0 6 online 79GB 1.03TB 92.99 1.11TB

There is no snapshots.

In Storage>Volumes it shows:

Name Aggregate Status Available space Used % Total space

vol1 aggr0 online 84.12GB 90 1T

We create volume level snapshots.

In snapshot copies:

Name Date Time Total Size Cumulative Total Size Status Dependency

nightly.0 10/26/2012.. 2.29GB 2.29GB Normal None

.....

In space tab:

Data space: 470GB

Snapshot copies space: 470GB (Including snapshot overflow: 265GB)

So basically we can only free space by deleting volume snapshots?

But we need to keep 3-4months old snapshots... So there is no other solution?

Also I don't think that we used 470GB of space for data.. I think at the moment we have used not more than 100-120GB.

thomas_glodde · ‎2012-10-26

hi there,

welcome to the world of netapp snapshots which keep CHANGED and DELETED data blocks (thats what backups -> snapshots are for).

to answer your question, yes, to really free up space you need to delete snapshots as well.

to answer your next question, no, it is not possible to delete a specific file only from a snapshot. you can only delete the snapshot as a whole.

Kind regards,

Thomas

MARIALIZ777 · ‎2012-10-26

Hi Thomas,

thanks for the answer.

Then it's better change backups strategy

I don't know if it's better to create new topic or ask here?

As you can see we mounted everything on same volume in FAS2020. It has total 1TB space.

So maybe it's better to delete snapshots and create few additional volumes.. ?

What we need is this:

There are several Moodle learning environment systems running on server. We need to keep their backups of mysql and moodledata for as long as possible.

Now I'm thinking:

Create one volume for php files and mysql. Snapshot this volume

Second volume for mysql backups (.gz files). Snapshot this volume

Third volume to store moodledata. Snapshot this volume

Maybe someone can provide good/effective backup strategy?

Thanks.

scottgelb · ‎2012-10-26

If you have different retention levels for different data types (php, mysql, archive, moddle) then that is a good reason to create a separate volume for each since snapshots are volume level.