My 2 cents worth. (Actual exchange rate will vary)
Using TSM's method of data storage we have about 3 bytes of data on tape for
every byte on a server. When we used a traditional backup method, we had
almost 9 bytes of data on tape for every byte on a server. The available dates
to recover to are about the same. We realized a real savings in media.
Moving from a weekly full to the always incremental allowed us to have fewer
tape drives to complete the same work. Our full backups required nearly 24
hours to complete, we no longer have to plan for a large weekend run.
Doing a restore with a traditional backup method means you restore a full
backup then up to 6 incremental backups, this can result in the same file being
written 7 times. TSM will restore each object only once. If TSM is properly
used this can save a great deal of time during the restore, if it is not
properly setup it can cost a great deal of time due to tape mount waits.
The downside is we no longer have 9 copies of an object on tape, we only have
two, so in theory the odds of losing an object due to bad tapes is larger, but
it is still a number starting with a dot and some zeros.
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Bernaldo de Quiros, Iban 1
Sent: Friday, July 14, 2006 5:42 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: [ADSM-L] Advantages of having backup by versioning...
Hi everyone there !!
Could someone explain me the principal advantages of having the backup
organised by versions...¿?
Is it really an advantage to others backup softwares such as Veritas or Legato
Thanks In Advance,
Iban Bernaldo De Quiros Y Marquez
Sun Microsystems, Inc.
Serrano Galvache, 56
Madrid 28033 ES
Phone +34 91 767 6233
Mobile + 34 659 01 91 12
Email Iban.Bernaldodequiros AT Sun DOT COM
De: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] En nombre de
Enviado el: viernes, 14 de julio de 2006 12:16
Para: ADSM-L AT VM.MARIST DOT EDU
Asunto: [ADSM-L] Retention of backup versions
I'm sure this question has been asked many times but I want to be sure what is
A mgnt class has been defined so that 5 versions of a file are kept, with a
retention of 30 days.
A file that is changed daily is backed up for 5 consecutive days. The next
backup is taken 3 months later.
What happens to the inactive files?
Storage and Database Administration
Systems Support Group, I.T.Division
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