Many big files in System Volume Information

Was monitoring an Exchange machine today and got a message that the Log disk contained less than x percent of storage. First thing to check if backups have run on the machine, because if those fail the log disk tends to fill up quickly. But the backups were OK and there was only a few hours of data on the disk. After short investigation it turned out to be the System Volume Information directory causing this and it had a lot of big files in it with a number of several GB each. Thing was most of these files were older than a year. So hereby a few quick commands:
First one to list the shadow copy space reserved and used for each disk:
vssadmin list shadowstorage
This got me some output and lets list here some stuff for the Log disk:
Used Shadow Copy Storage space: 52.481 GB (52%)
Allocated Shadow Copy Storage space: 52.983 GB (52%)
Maximum Shadow Copy Storage space: UNBOUNDED (100%)

Aha, so it had no limit and was already occupying over half the disk space and 52 GB. By the way the data disk was a factor 10 bigger in size and also had well over half the disk size used by only this stuff.
You can also open the Explorer and take the properties of the disk and look for the Shadow Copies tab. Also to make alterations.
In this case I used the available commands though. First I set the amount of disk space to use as maximum to only a few GB, which causes the old files to be deleted. Next I used the same command to raise the maximum space to be used again to a more suitable number.
vssadmin resize shadowstorage /on=E: /For=E: /Maxsize=19GB
So the above command sets the maximum size on the E drive to 19GB.
Sure got rid of the problem of Exchange management pack telling us during each day the Log disk was running below 50% free space already.
Very good, on to the next isue to be solved!
Bob Cornelissen