Thomas,

We had Commvault give a presentation here late last year.  Here is the good
and bad things I gathered up.

GoodStuff: Comvault has the ability to backup and restore indivudual
Exchange mailboxes and documents.  From what I remember you have the ability
to backup and restore Exchange up in 3 ways.  Supposedly MS uses this
product themselves for some of thier Exchange enviroment.

1)The full online backup/restore
2)Backup/restore at the mailbox level
3)Backup/restore at the document level

BadStuff: Comvault will have you belive that all of these backups take place
at the same blazing speed but anybody who has any experience with the ADSM
Lotus Notes 4.6 Agent knows differently.  You will take a GIGANTIC
performace hit if you do document level.  Expect the initial document level
backup to take a few days to finish.  Also expect your backup servers DB to
grow 3Xs its size when it started.  Normal everyday incremental backups will
probably take most of the night.  We did get them to admit that you would
see very serious performance hits you wanted to back Exchange up in any
other way than the Full Backup method.  The API Comvault uses is NOT a
Microsoft API so you can forget about any support from MS if you need to
recover.  Comvault becomes your support when you use thier product.

There would be no other reason to use Comvault unless you used its ability
to backup and restore individual mailboxes.  We were impressed with the
ability to do lower level backups in Exchange.  This would definitely be
useful because its a real pain to rebuild an Exchange server to get one
mailbox.  From past experience with the Notes agent it sounds like too high
of a cost.  We have been doing ok with the deleted item recovery so far.  I
would like to hold out for Exchange 2000 with its multiple information
stores and deleted the mailbox recovery additions.  At this time we have not
yet decided to test this product.

Jack