On Thu, 27 Mar 2003, Jin Bae Chi wrote:
>Suad, Thanks for your help. Let me see if I understand correctly.
>
>1. When you said putting db in backup mode, I can think of
>ARCHIVELOG mode for Oracle, which will take a few seconds and
>execute the flashcopy;
>Q: I heard flashcopy takes a lot less time to create a
>snapshot. Any analogy about how fast? How much time would you
>gain? Let's say mine takes an hour to hot-backup Oracle through
>TDP.
The database should already be running in ARCHIVELOG mode--you
can not make a useful hot/online backup without it. It is also
not something that can be changed while the database is open,
only when it is mounted, so switching between ARCHIVELOG and
NOARCHIVELOG mode would require taking the database down and up.
What Suad meant by putting the db into backup mode was to set
each of the tablespaces into archive mode by issuing the command
'alter tablespace TABLESPACENAME begin backup;'
Presuming that flashcopy is something similar to a Netapp
snapshot, you would put all of your tablespaces in backup mode,
execute the flash copy. Again, presuming it performs similar to a
Netapp snapshot, you should expect that process to be very
short--on the order of seconds to a minute or so depending on the
size of the database. Once the flashcopy is completed, you can
take the tablespaces out of backup mode ('alter tablespace TSPACE
end backup;'). At this point you can simplly transfer the
flashcopy files to TSM via a regular backup interface.
>2. Change to NOARCHIVELOG mode for Oracle and mount pseudo volume and backup that
>filesystem.
>Q: Should I create a separate set of disks for fs (pseudu vol)? Can I do LV backup?
>Q: Can I use, after backing it up, the same fs for testing or report purposes before
>delete it?
>
>Sorry for too many questions. Thanks again.
Hmmm, not quite sure what you're asking here, but I would
recommend a trip through the Oracle docs regarding standby
databases if what you want is a separate reporting instance.
