To add to what Wanda is saying:
When a FlashCopy is initiated, the DB/Mail server that you are flashing should be
quiesced prior to the FlashCopy being initiated.
FlashCopy can also be expensive.
-----Original Message-----
From: Prather, Wanda [mailto:[EMAIL PROTECTED]
Sent: Tue 9/14/2004 10:55 AM
To: [EMAIL PROTECTED]
Cc:
Subject: Re: TDP vs. FlashCopy thoughts
I am not an expert in this area, but I think there are several issues
involved.
FlashCopy is taking a physical image of the VOLUME(s) involved.
The Data Base manager doesn't know you're doing it.
SO while it's easy and low cost to do the FlashCopy (it's pretty much an
outboard hardware process), it doesn't copy or clear the logs that the DB
management system uses.
So the real question, as usual, WHAT are your recovery requirements?
What are you going to do with that FlashCopy if somebody wants to restore
the data base?
If what they want is the ability to back out a bad transaction, you can do
that with Oracle (for example), by restoring from the last full and then
rolling forward from the journal, but you won't necessarily have a copy of
the journal if all you have is a FlashCOpy.
And Exchange and SQL server (I think) work like the TSM DB, when you take
the DB backup, they clear their transaction logs. So you would have to have
some way to sync up your logs, if you used FlashCopy instead.
SO you gotta work those issues out. FlashCopy certainly is a great option
for a DB manager that doesn't HAVE a TDP available, because you can stop
your DB for just a few SECONDS and take a FlashCopy, instead of having the
DB down for an hour to dump the volume as a flat file.
Talk to your DBA about the recovery requirements for your particular DB's.
WandaWanda Prather
"I/O, I/O, It's all about I/O" -(me)
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] On Behalf Of
Mike
Sent: Tuesday, September 14, 2004 11:42 AM
To: [EMAIL PROTECTED]
Subject: TDP vs. FlashCopy thoughts
Given that TSM has TDP for many databases and that TDP can do
incremental backups at the record level. What are the thoughts
for using TDB vs. using FlashCopy on an ESS/Shark? The FlashCopy
must backup the entire database each time, unless the backup
database could be mounted to a secondary server that could then
start TDP on the backup copy...?
Mike
