We use the TSM subfile backup for backing up windows 2000 servers over a
WAN network. And it helps, really helps.

We have run into four problems, Three of them are design issues:

1) The subfile cache, which is located on the client to store the checksums
for each block of a backed up file. This cache has a max size of 1024megbytes
and we have cache's that max out. I am not sure what effect this has on the
subfile functioning, but it does take a bit of disk space.
It would be nice to know what effect on the subfile  backup process maxing
out the subfile cache has.

2) The max file that can be handled by the subfile backup is 2gig, and we have
folks who have larger files. It would be good if IBM could lift this limit.

3) If the delta file grows beyond a fixed size of the base, the file is
backed up again to create a new base. This puts a hurt on the network. It
would be good if the TSM server could build a new base file on the server using
the old base and the delta.

4) We had a problem with a couple of restores, when the size of the base file
and the delta file exceeded 2gig the restore would fail. This is fixed in the
latest client levels.


This was a great new feature for TSM. I hope they keep up the work.

len