I'm trying to get a report that breaks out the following space usage values for each volume: Allocated to LUNs, Reserved for Snapshots, Unallocated Space, LUN Space Used, Snapshot Space Used, & Snapshot Count.
The tricky value seemed to be getting LUN Space Used (how much space in the volume is being used by data and/or files). In most reports that have any kind of "Space Used" value, it refers to how much space in the volume has been allocated to LUNs, I'm trying to get a report that also gives an indication of how full those LUNs are. Then I thought I had found everything I needed by scheduling the Volume Space Breakout report (in Operations Manager) to send an xml file that included all fields, I was able to map the fields like so:
|My Report||xml field|
|Total Size||dfKBytesTotal + volSnapshotReserveSpaceTotal|
|Allocated to LUNs||dfKBytesUsed|
|Reserved for Snapshots||volSnapshotReserveSpaceTotal|
|LUN Space Used||dfKBytesData|
|Snapshot Space Used||volSnapshotReserveSpaceUsed|
This initially seemed to work, but then I noticed that some of the LUN Space Used values were no longer accurate after a day or two, they had a value higher than they should've been (e.g. the report would show "4 GB" when all the files actually added up to 3 GB). It seems the dfKBytesUsed field in the xml report only increases in value, never decreases, so my report ends up showing a "high water mark" for each volume instead of a current value.
Is this a bug in the Volume Space Breakout report? Or am I misunderstanding what the dfKBytesData field actually refers to? If so, is there a field in a different report that will get me what I need?