VSS not detecting removed snapshots
On my win2003 server (patched), I have observed following:
1. Using vshadow.exe utility from latest VSS SDK 7.2, create 5
snapshots of volume E:
../vshadow.exe -p -nw e:
(repeat 5 times)
2. Using volperf.exe /install, from Win2003 Resource Kit, install the
VSS performance counters
3. Use perfmon to monitor the "Shadow Copies" object, namely the: "Nb
of shadow copies", it should display 5 after step 1)
4. Using vshadow.exe, list the shadow copies and remove the MOST RECENT
ONE (or the one from the middle of the list)
5. In perfmon, observe the number of shadow copies, the number DID NOT
6. Using vshadow.exe, list the shadow copies and confirm the one
removed in step 4 is no longer visible.
7. Using vshadow.exe, remove the OLDEST shadow copy
8. In perfmon, observe the number of shadow copies, the number
decreased BY TWO.
Conclusion: The removal of non-oldest shadow copy does NOT decrease the
number of shadow copies.
The removal of oldest shadow copy triggers the update of this counter
Can anyone point to some Microsoft document explaining above
Without explanation, I am considering this a bug, because the number of
snapshots is important number which may reach it's maximum (512) and
may cause VSS to remove the oldest copies, even if user has taken care
and already removed some of it's snapshots for the periods it deemed
non critical. The user may keep the count of snapshots, and vssadmin
will also confirm that, but actual number of snapshots, without removal
of oldest one, will be way over it, and may reach the max 512 and cause
unwanted removal of oldest snapshots.