ONTAP Discussions

Free Space difference between NetApp and WmWare

ELESSARIN
8,852 Views

Hello,

We are using ESX 4.1 with VmWare vSphere Client. Datastores are set on a NetApp FAS 2040.

Problem : we have space difference between VmWare view and NetApp view :

The volume size is 1 TB and there is only one LUN of 900 GB in this volume. And the datastore use all 900 GB of this LUN.

In this datastore, I have 77.57 GB of free space in VmWare view but if I check volume free space in NetApp System Manager, I have 418,36 GB of free.

Deduplication saved 265,67 GB (30 %) on the volume.

There is no snapshot.

Why is Vmware not showing all the free space ?

VmWare NetApp plugin :

Here, it is strange that Datastore Usage is not equal to Lun usage.

NetApp System Manager :

I don't think that it is a space reclaimation issue because NetApp is showing more freee space.

Thank you for your help.

1 ACCEPTED SOLUTION

__COLIN_GRAHAM_14270
8,852 Views

If you have dedupe switched ON for a volume with a LUN, the space reclaimed from dedupe is released back into the volume/aggr. in order to use the extra space you need to expand the lun beyond the 1tb size of the volume.

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5 REPLIES 5

__COLIN_GRAHAM_14270
8,853 Views

If you have dedupe switched ON for a volume with a LUN, the space reclaimed from dedupe is released back into the volume/aggr. in order to use the extra space you need to expand the lun beyond the 1tb size of the volume.

ELESSARIN
8,852 Views

Thank you for this explaination. Now I understand why Datastore is greater than Lun usage.

But I have an other volume where Lun usage is greater than Datastore :

Space reclamation or display bug ? If it is a space reclamation, how can I check it ?

Thanks

Darkstar
8,852 Views

This happens if you delete files (or snapshots) from inside your LUN. ESX only marks the blocks as "free" but on the NetApp, they still contain the old data and are thus "used". There's no easy way to "reclaim" this space on the filer, at least not on ESX.

-Michael

eric_barlier
8,849 Views

If you were to use VmWare on NFS you wouldnt have this complexity. Free space would be free space, easy.

Eric

ELESSARIN
8,849 Views

Hello,

Finally I have upgrade NetApp plugin for vSpere Client to 2.1.2 and this view is correct now. It was a bug in previous version.

Also there is a space reclaimation problem with NetApp as mentioned. 2 solution to correct it :

1 - Migrate to vSphere 5

2- Create a new blank datastore and use function clone or convert to move VM

Thanks.

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