How to reclaim free space in Aggr?

[balazs_lovas]

Hi,

I'm still trying to grasp NetApp's storage technology, so my question might be dumb >(

This is the setup

• aggrage with no snap reserve and a single volume
• the volume is set to none space reservation, 100% frac.res.
• a single lun is created on the volume

The storage is producing the expected behaviour: the volume size is not reserved from the Aggregate. As I pump data onto the LUN, the data is getting stored, and the aggregate shows increased USED capacity.

Now, I would expect that if I delete data from the LUN the Aggrage's used capacity should became smaller (it should get smaller). However this is not happening at all.

So when I upload 2gb to the LUN (from a windows box), the aggreagate used capacity shows 2gbs. When i delete the files from the LUN, the aggregate doesn't go back to 0.. it is still showing 2gb as occupied capacity. If I do this upload/delete sequences from the windows box, that aggregate gets bigger, and bigger...

So how can I reclaim that used and deleted space from the aggr?

Thanks

[BrendonHiggins · Accepted solution]

Hi, welcome to NetApp world.  Give it a couple of months and it will all make sense.  Have a read of this on Frac. Res.

http://communities.netapp.com/groups/chris-kranz-hardware-pro/blog/2009/03/05/fractional-reservation--lun-overwrite

To get it back you need to run the space reclaimer which is a tool on the newer SnapDrive product.  However it should happen automatically as the system fills up.

Hope it helps

Bren

[fajarpri2]

Hmm interesting.

This is new to me. I experienced this too.

No wonder I got a feeling the available space is getting smaller and smaller eventhough I delete files.

[BrendonHiggins]

There is more information on the space reclaimer here.

http://now.netapp.com/NOW/knowledge/docs/snapdrive/relsnap61/html/softwa

re/admin/GUID-721BA2A1-042E-49A4-85A5-DA734B3D1FE3.html

Bren

[fajarpri2]

Can pls enlighten a newbie like me?

1. I use iSCSI connected to a ESXi host. Is the space reclaim still the same? Using Snapdrive tool from Windows?

2. Is there any CLI in the Data Ontap directly to reclaim the space?

Thanks in advance.

[balazs_lovas]

Hi,

Thanks everyone for the info!

This behaviour really makes me crazy .

I'm using VMware so the windows snap manager is out of question. I wonder if the host utilities for vmware or the new snap manager for VI includes some similar funcionality.

Has any you tested it already?

[BobGanz]

I to am having the same issue, you would think there would be a process running in the back ground every hour or so to reclaim space. As well as other limitations with the OS i am learning. Not sure the OS is really mature enough yet. A work in progress. I migrated from a Dell Equallogics and management of that system is light years ahead of NetApp. LLAP