IMHO, NetBackup and TSM are so different, that they are hard to
compare. If one comes from one environment and then tries the other,
the other will look bad.
I come from a dozen years with TSM and its predecessors and have now
used NBU for about 3 years.
IMHO, TSM and NetBackup are both fairly well funded products designed to
work in a myriad of settings. To me, the biggest difference is that TSM
can be setup to run totally automatically, with manual intervention
necessary only when you run out of resources such as enough disk or
tape. I would go weeks or months without having a problem or having to
touch or look at the system. NetBackup, on the other hand, is
incredibly in need of hand-holding and getting it out of bad
situations. I've had nights where everything went well, but I've never
had a week where everything went w/o intervention. This is a shop with
a couple of terabytes of data and about 100 clients of most every
variation.
For example, this has been a particularly bad week, with an (LTO-1)
drive going bad. NetBackup has used over 20 hours of my time this week
and I've restarted it several times due to apparently hung jobs. One
day last week a (VAULT) duplication job seemed to hang. It had chosen
to duplicate a tape (first of several) that was still in use by a
long-running backup. One day last week I defined a disk staging
storage group and tried to test it using a test policy. Many of my
production backups crashed and burned that night, complaining about no
storage group available. They are all set to use a specific storage
group, but somehow this didn't matter.
TSM uses a real database internally and has an excellent SQL query
interface to everything. Back up the DB at any time and you get a valid
dbbackup. TSM was built to backup to disk and migrate to tape, so its
disk staging is a decade ahead of NetBackup.
Of course, the biggest difference, after managability, is that TSM never
backs up the same file twice. This means that you can successfully
backup file systems over slow links, even though you'd never attempt a
restore over that slow link.
I could answer most of the points by the recent poster that doesn't like
TSM, but I don't find that helpful given what I have written above.
Your experiences may vary substantially!
Pardon me while I go restart NetBackup to eliminate the 6 current hung
Active jobs, so those machines will backup tonight (I *think* they are
hung because one of my 4 drives is in DOWN status and the main storage
group was set for a maximum of 4 drives when they were scheduled.
That's only a conjecture though, as I haven't seen a clue as to what
those 6 jobs are waiting for ... even though having debug level 1 set
and all log directories defined. :-(
