Aggregate-Volume used space mismatch



We have a problem where used space on our aggregate does not equal the total sum of used space for all volumes.


Filer1> df -Ag
Aggregate                      total              used      avail capacity
aggr0                               9699GB     6042GB     3657GB      62%
aggr0/.snapshot            0GB        0GB        0GB     ---%

Filter1> df -sg
Filesystem                      used      saved       %saved
/vol/vol0/                           5GB        0GB           0%
/vol/vol_vmware_nfs/     8456GB     2058GB          20%

As you can see there is approx 8.4TB of space used by all (thin provisioned) volumes, but only 6TB used on the aggregate.


Even taking away the 2TB of de-dupe savings, there is still nearly 500GB that appears to have gone "missing". Can anyone explain what might be going on here?


I have checked and there are no snapshots currently on the volume.



Re: Aggregate-Volume used space mismatch

If you want to go for exact caliculation, go for mb or kb level. Then only you will get exact caliculation. NetApp will prefer round figures. If you have a 1GB volume and that is used 900MB but if you check t with df -g it will show u as 0 only.


df -Am


df -m

Re: Aggregate-Volume used space mismatch

Also post output of "aggr show_space".

Re: Aggregate-Volume used space mismatch

Hi, thanks for the replies. Here is the output. It looks like aggr show_space shows the actual used space of the volume vol_vmware_nfs. Can you help me understand why there is such a difference between the two outputs (9.2TB with df-m and approx 6.6TB with aggr_show_space?)


Aggregate                total       used      avail capacity
aggr0                9932067MB  6757124MB  3174943MB      68%
aggr0/.snapshot            0MB        0MB        0MB     ---%
Filer1> df -m
Filesystem               total       used      avail capacity  Mounted on
/vol/vol0/            157593MB     6106MB   151487MB       4%  /vol/vol0/
/vol/vol0/.snapshot     8294MB      293MB     8001MB       4%  /vol/vol0/.snapshot
/vol/vol_vmware_nfs/ 10485760MB  9200257MB  1285502MB      88%  /vol/vol_vmware_nfs/
/vol/vol_vmware_nfs/.snapshot        0MB   507180MB        0MB     ---%  /vol/vol_vmware_nfs/.snapshot


Filer1> aggr show_space
Aggregate 'aggr0'

    Total space    WAFL reserve    Snap reserve    Usable space       BSR NVLOG           A-SIS          Smtape
  11300486144KB    1130048612KB             0KB   10170437532KB             0KB     103664352KB             0KB

Space allocated to volumes in the aggregate

Volume                          Allocated            Used       Guarantee
vol0                          171898376KB       6000312KB          volume
vol_vmware_nfs               6643458956KB    6607153892KB            none

Aggregate                       Allocated            Used           Avail
Total space                  6815357332KB    6613154204KB    3250943096KB
Snap reserve                          0KB             0KB             0KB
WAFL reserve                 1130048612KB     123729496KB    1006319116KB



Re: Aggregate-Volume used space mismatch

My best guess is that this is deduplication effect. I.e. logically your files require about 9000GB on volume; but actual space consumption on aggregate level is reduced due to deduplication.