topic Re: LUN Space Reservation: disabled, but not giving space back to the volume in Data Protection

LUN Space Reservation: disabled, but not giving space back to the volume

txskibum2000 — Thu, 05 Jun 2025 06:49:04 GMT

So, I have a weird issue...

I have a 135Gb Volume called "ctxlic_db". The volume guarantee is enabled, with 0 fractional_reserve.

I have a 100Gb LUN called "ctxlic_db.lun" in the volume with space reservation disabled.

LUN is attached to a Win2003 host. The windows host shows the drive/lun is using just under 7Gb (93Gb free).

The 135Gb Volume, with 43Gb of Snapshots, show 88% full, using 118Gb space!?

So, my question is, why is my volume showing 88% full, when LUN Space Reservation is disabled, and the host is using only 7Gb.

I would generally expect the volume used space being 50Gb (7Gb used space + 43Gb of snapshots).

Details below and attached.

Thanks!

fa02> vol status /vol/ctxlic_db

Volume State Status Options

ctxlic_db online raid_dp, flex nosnap=on, create_ucode=on,

convert_ucode=on, no_i2p=on,

fractional_reserve=0

Containing aggregate: 'fc_aggr1'

fa02>

fa02> lun show -v /vol/ctxlic_db/ctxlic_db.lun

/vol/ctxlic_db/ctxlic_db.lun 100.0g (107389255680) (r/w, online, mapped)

Comment: "I"

Serial#: W-OPKZYMnCUu

Share: none

Space Reservation: disabled

Multiprotocol Type: windows_gpt

Maps: viaRPC.iqn.1991-05.com.microsoft:ctxlic.aaefcu.org=5

fa02>

fa02> df /vol/ctxlic_db/ctxlic_db.lun

Filesystem kbytes used avail capacity Mounted on

/vol/ctxlic_db/ 141557760 124558928 16998832 88% /vol/ctxlic_db/

/vol/ctxlic_db/.snapshot 0 45575696 0 ---% /vol/ctxlic_db/.snapshot

fa02>

fa02> df -h /vol/ctxlic_db/ctxlic_db.lun

Filesystem total used avail capacity Mounted on

/vol/ctxlic_db/ 135GB 118GB 16GB 88% /vol/ctxlic_db/

/vol/ctxlic_db/.snapshot 0GB 43GB 0GB ---% /vol/ctxlic_db/.snapshot

fa02>

LUN Space Reservation: disabled, but not giving space back to the volume

gridley — Tue, 02 Aug 2011 14:28:30 GMT

Have you written data to the LUN and then deleted it? You will need to run space reclamation from SnapDrive if so to get the space back.

LUN Space Reservation: disabled, but not giving space back to the volume

jakob_bena — Tue, 02 Aug 2011 14:30:42 GMT

hi,

you can use the option of your snapdrive tool called spacereclaimend. this will refresh the used space of your volumen.

on filer site you can use wafl reallocate, but i think for you it is the best way to do this with the snapdrive option.

regards

LUN Space Reservation: disabled, but not giving space back to the volume

txskibum2000 — Tue, 02 Aug 2011 14:31:55 GMT

This is what I was thinking, thank you for your reply.

I tried to run Space Reclamation twice (via Snapdrive), and it would get to 3-4% (10-15minutes), then quit running.

LUN Space Reservation: disabled, but not giving space back to the volume

gridley — Tue, 02 Aug 2011 14:34:59 GMT

No worries, happy to (try to ) help!

As I recall there are things that will stop SR from running. such as snapshots being taken. I will have a search and see if anything useful turns up.

It might be worth opening a case if you have time, so we can get you your storage back!

Re: LUN Space Reservation: disabled, but not giving space back to the volume

gridley — Tue, 02 Aug 2011 14:39:30 GMT

EDIT: just saw your reply, so this isn't relevant!

From the docs:

https://now.netapp.com/NOW/knowledge/docs/snapdrive/relsnap63/html/software/admin/GUID-1F3DD258-F601-4CAE-B765-05507F76A493.html

"SnapDrive for Windows automatically stops Space Reclaimer in several instances.

During any LUN management operation on a LUN running Space Reclaimer, including LUN disconnect and LUN delete operations
During any Snapshot copy management operation except Snapshot copy rename and delete
On all LUNs of the same storage system volume during Snapshot copy creation
If the SnapDrive service is stopped
During LUN restore operations for any volume mount points directly or indirectly mounted (cascading) from the disk being restored
During Windows host cluster failoverIf a host cluster failover operation occurs on a Windows Server 2003 MSCS or Windows Server 2008 failover cluster while Space Reclaimer is running on a shared LUN, space reclamation will stop running on that LUN.
During any MPIO path management operations, including adding or removing an initiator or active path selection"

Did any of this happen?

Re: LUN Space Reservation: disabled, but not giving space back to the volume

txskibum2000 — Tue, 02 Aug 2011 14:39:38 GMT

Thanks.

I have read the "Reasons for SnapDrive to automatically stop Space Reclaimer", and none of those reasons apply to me.

I will open a case with NetApp.

LUN Space Reservation: disabled, but not giving space back to the volume

txskibum2000 — Tue, 02 Aug 2011 21:29:37 GMT

Support has refered me to KB 3011577, which i have read, and has suggested to create a new LUN... NDMP copy the data from the old LUN to the new LUN, and attached to the new LUN -destroy the old LUN. I figure this would be the recommendation...

Thanks all!

LUN Space Reservation: disabled, but not giving space back to the volume

gridley — Wed, 03 Aug 2011 09:39:00 GMT

Completely random thought - I wonder if the LUN move functionality would achieve the same resullt? Probably something to test in a different environment... I imagine not since it uses mirroring instead of an NDMP copy.