Why do volume physical and used capacity slightly differ sometimes?

[skellner]

Hi,

I try to figure out what the different fields in OM include. In the following report physical and used capacity differ sometimes but I have no idea why. Any hints?

Thanks in advance

v100spldv02:~ # dfm report view sk_vol standort/hannover

Volume                    Aggregate Total (GB)   Physical (GB) Used (GB)   Effective (GB) Reserved (GB) Savings (GB) Volume Space Guarantee

------------------------- --------- ------------ ------------- ----------- -------------- ------------- ------------ ----------------------

backuptestq071            aggr0               75            50          50             50             0      0 bytes

common_nfs_002            aggr0               60             0           0              0             0       335 MB file

q005_its_001              aggr0              250           217         217            285             0      68.0 GB file

q007_its_001              aggr0              150           114         115            149             0      34.6 GB file

q010_its_001              aggr0              190           126         130            170             0      43.6 GB file

q011_its_001              aggr0             1200           873         875           1206             0       332 GB file

q012_its_001              aggr0              400           332         333            420             0      88.6 GB file

q013_its_001              aggr0              120            77          78            108             0      30.2 GB file

q015_its_001              aggr0              240           185         186            231             0      45.4 GB file

q017_its_001              aggr0             1600          1053        1056           1540             0       487 GB file     <------ ???

q018_its_001              aggr0              110            66          66             97             0      31.0 GB file

q020_its_001              aggr0              350           270         271            351             0      81.1 GB file

[kryan]

You can refer to the "Help --> About this page" topic in the OM GUI for details about report fields on the report currently being viewed.

[skellner]

Thanks for your answer. Unfortunately physical and effective are not explained and these are the ones that I search for.

[kryan]

This appears to be a Volume Report.

http://DFMSERVER:8080/help/monitoring/rpt_vol.htm

Volume reports

The Volume reports display information about all volumes and their performance characteristics.

This table lists and describes all fields in the Volume reports.

Effective Used

The active file system (AFS) data in the volume without deduplication space savings,  that is, if deduplication was not enabled on the volume.

Physical Used

The active file system (AFS) data in the volume with deduplication space savings.

[kjag]

Also the "Savings" due to dedupe will not be accounted for Physical used space.

[kjag]

Hi,

Just check if your snapshot space is overflow in to the data space of volume. AFAIK this is not considered as physical used.

Also if you create a space guaraneed lun(but its not actually consumed, i.e used space is zero), then the physical data size will less than the actual size.

-KJag