Subject RE: [Firebird-Architect] Re: Services API
Author Leyne, Sean

> <view type=opposing>
> If you want to put a backout off site -- in a bank vault or under your
> pillow -- gbak is your baby.
> </view>

I can't see how the location of where the backup is going makes a

I could see an argument about the nature of the data you want to store
-- a database image vs. a data/schema extract, but that it a completely
different point.

Further, if you have a 50GB+ database, how long do you want to wait for
the GBAK backup to run?

Worse yet! How long are you prepared to wait for the restore?

For a 50GB+ database, in either case you're talking many, many hours!

A backup which takes hours to run and enough longer to restore is of
limited value for most recovery purposes -- admittedly, there are some

In the case of a level 0 (full) NBackup;
- the backup time is almost completely server I/O disk speed dependent

- the restore time,
- if the backup is on the local server, is instantaneous. Simply
rename the old database, rename the backup file and go.
- otherwise, it is as long as it takes to transfer from the
external source (other server, NAS, SAN, tape drive) to the local

In the case of a level 1+ (incrementals) NBackup;
- the backup time is still server I/O disk speed dependent
- the restore time, after the backup file has been localized, is also
server I/O disk speed dependent, since the incremental backups must
selectively replace database pages in the target database, from the
backup file.

Finally, remember one of the features of NBackup is not to perform a
backup at at! It can simply place the database into a mode which allows
for the database file to be backed-up/copied is place (to tape). In
fact, a level 0 backup does exactly that as well as actually creating
the file copy.

Thus, you can get an image copy of the database and put that under your
pillow -- personally, I can't see anything that beats an image copy of a
database for true peace of mind!