Recovering space back into aggregate

[RANJBASSI]

Hi All

We have a FAS8020 running Data ONTAP 8.2.1 7 mode and have a question on how space gets reclaimed on the Netapp. 

So I have made some adjustments and deleted some volumes which were no longer required but am sure I am not seeing that space being put back into the aggegate. 

Is there a process I need to do to reclaim this space or does the NetApp run system tasks to give back the storage consumed back to the aggregate?

Thanks

[deepuj]

Hi,

Was the volume you deleted thin provisioned with less usage? Do you have Aggregate level snapshots ?

Thanks

[RANJBASSI]

Hi 

Yes all of our volumes are thin provisioned. We would have used snapshots at the volume level but I would assume when the volume is deleted the corresponding snapshots with that volume also disappear? 

Thanks

[deepuj]

Hi,

1)Is the volume thin provisioned, and barely used? If , yes the deletion of volume will not add any space to the containing aggregate. 

2)Check if there is any aggregate level snapshots are present, space should come back when you delete it.

What was the size of aggregate you deleted? does priv set advanced ; wafl scan status show space reclamation running? 

Thanks

[RANJBASSI]

Hi

Yes I wasnt even aware the aggegate does snapshots, where is this defined? I have typed snap list -A and this give me the following out: 

%/used %/total date name
---------- ---------- ------------ --------
0% ( 0%) 0% ( 0%) Nov 11 09:00 hourly.0
3% ( 2%) 2% ( 2%) Nov 11 00:00 nightly.0
3% ( 0%) 2% ( 0%) Nov 10 19:00 hourly.1
4% ( 1%) 3% ( 0%) Nov 10 14:00 hourly.2
4% ( 1%) 3% ( 0%) Nov 10 09:00 hourly.3

Is this what you mean by aggregate level snapshots? 

Where are these parameters normally set? if I use OCUM and go to aggregates there is no 'snapshots' section. 

What was the size of aggregate you deleted? does priv set advanced ; wafl scan status show space reclamation running? #

This is my output, I assume its running

Volume vol0:
Scan id Type of scan progress
2 active bitmap rearrangement fbn 187 of 335 w/ max_chain_len 3
Volume NETAPP_prf1_esx_w2k8_sas_03:
Scan id Type of scan progress
3 active bitmap rearrangement fbn 21141 of 31982 w/ max_chain_len 3
43131 block ownership calculation block 11856 of 31982
43132 snap create summary update block 1500 of 31983
Volume NETAPP_prf1_esx_w2k8_sas_02:
Scan id Type of scan progress
4 active bitmap rearrangement fbn 10466 of 16974 w/ max_chain_len 3
Volume NETAPP_prf1_esx_w2k8_sas_05:
Scan id Type of scan progress
5 active bitmap rearrangement fbn 7391 of 12753 w/ max_chain_len 3
Volume NETAPP_prf1_esx_w2k8_sas_01:
Scan id Type of scan progress
6 active bitmap rearrangement fbn 7066 of 14028 w/ max_chain_len 3
Volume NETAPP_prf1_esx_w2k8_sas_06:
Scan id Type of scan progress
7 active bitmap rearrangement fbn 13647 of 18672 w/ max_chain_len 3
Volume NETAPP_prf1_esx_w2k8_sas_04:
Scan id Type of scan progress
8 active bitmap rearrangement fbn 15700 of 16974 w/ max_chain_len 3

Thanks

[RANJBASSI]

I been looking at the snapshots on volumes on the source filer and appear to see some odd things:

We currently use VSC for VMware to perform snapmirror updates on a retenion of 7 days, these are shown as smvi_****** which are fine.

We also have a snapmirror job which runs every few hours which is also shown right on the top line. 

What I dont get is the snapshots going back to June/May. Are these safe to delete? or is one of these like a baseline snapshot which the other snapshots are dependent on? 

I am thinking if these are not required, these snapshots are quite large in size and could be the reason why the space is being taken on the aggregate.