Most of the database backups will be Oracle databases.  Currently we do not
have the option of using TDP, so we will either take hot or cold database
backups.  If space permits we will backup to disk first then start the
dsmc.  The main database recovery requirement is consistency between files,
so the restored files must all come from the SAME backup.





Daniel Sparrman <daniel.sparrman AT EXIST DOT SE>@VM.MARIST.EDU> on 29/04/2002
14:37:05

Please respond to "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>

Sent by:  "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>


To:   ADSM-L AT VM.MARIST DOT EDU
cc:

Subject:  Re: archive or incremental backup type


Hi

Incremental = Minimizes your backup window, as only changed files are
moved. However, you could activate subfile backup, which means that only
the changed part of the file is backed up. Incremental works best with
smaller files, as large files requires that the complete file is backed
up. Subfile cache would perhaps work good also with large files, as only
the changed part of the file is backed up. However, normlly a database
doesn't work as ordinary large file, as there is to much changes in the
"file".

Archive = Best for storing files for a specific amount of
days/month/years. However, archiving is like doing full backups all the
time, which makes a cost in backup time.

Normally for databases, you use a TDP to minimize the time required for
backup. Different types of TDP:s have different ways of backing up;
differential, incremental, log archiving, full backups and so on. But, if
you do hot backups, it's recommended to use TDP:s, as a file backup client
doesn't work 100%(some files may have been locked by the application
during the backup. This can be solved by using Dynamic setting, but this
doesn't automatically mean 100% consistency when trying to restore).

It would be easier to do a recommendation if you told us what kind of
application you are using. For some applications, doing
incremental/archiving works great, for some it's a disaster.

If you still insist on using file backup/archive client, I'd recommend
using cold backups, using archive. This could be done on perhaps a weekly
basis.

Best Regards

Daniel Sparrman
-----------------------------------
Daniel Sparrman
Daniel Sparrman
Exist i Stockholm AB
Propellervägen 6B
183 62 HÄGERNÄS
Växel: 08 - 754 98 00
Mobil: 070 - 399 27 51




George Harding <George_Harding AT ENTUK.CO DOT UK>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
2002-04-29 10:51
Please respond to "ADSM: Dist Stor Manager"


        To:     ADSM-L AT VM.MARIST DOT EDU
        cc:
        Subject:        archive or incremental backup type




I would like to get some advice on the advantages / disadvantages of
archive versus incremental backup types.
The files I am backing up are database files so in general are large and
need to be restorable to point in time for consistency.

Thanks