Data ONTAP Discussions

Lun and volume free space difference

Dear all,


My system is FAS 2552 in c-mode 8.3.2

For my vSphere cluster I have 4 1TB LUNs in VMFS. Each LUN is in one think provisionning volume of 1.2TB. Deduplication is enable


I don't understand why I have more free space on my LUNs instead of my volumes ?

For example : my LUN1 have 380GB free space but volume have only 151GB free space. This night I move many data in a virtual machine (approximately 200GB), my VMs are in think provisionning. This morning my datastore is down Smiley Mad  When I see the free space, the LUN is ok but my volume is full. How it is possible my volume was full while my LUN is smaller than my volume ans not full ?


Thanks for your explanations







Re: Lun and volume free space difference

I'm having difficulty following the wording of your question.  Are you trying to say that these are THIN or THICK provisioned volumes?


Also - are you going by the vCenter/Host reporting of LUN space or by Netapp/Sys Mgr?  I've learned that you should ALWAYS go by the HOST's perspective when it comes to determining the utilization of LUNs... this is true of ANY storage vendor.

Re: Lun and volume free space difference

Sorry for my English Smiley Frustrated

My volumes are thin. The problem is not the free space on my LUN but on my volume. How can I no longer have free space in my volume while on my LUN there are still ? My LUN is smaller than my volume...

The view is in NetApp Data Ontap



Re: Lun and volume free space difference

Nobody to answer me ? Man Sad

Re: Lun and volume free space difference

Sounds to me like you have snapshots enabled without knowing it and/or a lack of fractional reserve. You need to leave enough space free in the volume to account for overwrites and snapshots.


Fractional reserve info: