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richard102
Starting Member
25 Posts |
 Posted - 2009-02-24 : 11:15:46
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| Hi Alljust reading about Differential backups. Which is correct please?1) A differential backup only backs up new and changed data since the last full backup.2) A differential backup only backs up new and changed data since the last differential or full backup.Option 1) seems to be written alot, but I feel if we do a full backup on a friday, and differential backups every other day we don't really need to record 'mondays' data again on tuesday, wednesday etc.Restoring I feel should initially be of a 'base' full backup then sequential differential backups from monday / tueday / etc. Not 'restore the base then the last good diff'.This subject is of interest to me as I'm looking at ways to use less disk-space whilst still doing nightly backups (and btw 6 hourly tlog backups), and if all but the most current diff backup are redundant - that's just wasteful (to me).thanksrichard102 |
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sodeep
Master Smack Fu Yak Hacker
7174 Posts |
Posted - 2009-02-24 : 12:14:53
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| Option 1 is correct. We do 1)Fullbackup every week2)Differential Backup Every day3)Transactional Log backup every 15 mins |
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ahmad.osama
Posting Yak Master
183 Posts |
Posted - 2009-02-24 : 13:02:10
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quote:
Originally posted by richard102
Hi Allrestoring I feel should initially be of a 'base' full backup then sequential differential backups from monday / tueday / etc. Not 'restore the base then the last good diff'.richard102
Well....the current behavior of the differential backups has less maintenance overhead...otherwise u need to manage each differential backups in order to restore them when required...If you want to save space..then you can delete differential backups prior to a full backup..that is done every sunday....this can be automatically...and can also be scheduledRegards,Ahmad Osama |
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sodeep
Master Smack Fu Yak Hacker
7174 Posts |
Posted - 2009-02-24 : 13:07:02
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quote:
Originally posted by ahmad.osama
quote:
Originally posted by richard102
Hi Allrestoring I feel should initially be of a 'base' full backup then sequential differential backups from monday / tueday / etc. Not 'restore the base then the last good diff'.richard102
Well....the current behavior of the differential backups has less maintenance overhead...otherwise u need to manage each differential backups in order to restore them when required...If you want to save space..then you can delete differential backups prior to a full backup..that is done every sunday....this can be automatically...and can also be scheduledRegards,Ahmad Osama
Incorrect. You only need last differential backup along with Full backup to restore. Also backups can be removed or placed to tape once Full backup is successfully completed in weekend. |
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ahmad.osama
Posting Yak Master
183 Posts |
Posted - 2009-02-24 : 13:27:47
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quote:
Originally posted by sodeep
quote:
Originally posted by ahmad.osama
quote:
Originally posted by richard102
Hi Allrestoring I feel should initially be of a 'base' full backup then sequential differential backups from monday / tueday / etc. Not 'restore the base then the last good diff'.richard102
Incorrect. You only need last differential backup along with Full backup to restore. Also backups can be removed or placed to tape once Full backup is successfully completed in weekend.
I think I was unable to communicate my point...quote:
Well....the current behavior of the differential backups has less maintenance overhead...otherwise u need to manage each differential backups in order to restore them when required...
by this i meant to say that u only need to maintain the last differential backup as this is only required when restoring and if there wud have been the other way round then one has to restore the seven differential backups in strategy discussed in the post....and it wud have been an overhead......Regards,Ahmad Osama |
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sodeep
Master Smack Fu Yak Hacker
7174 Posts |
Posted - 2009-02-24 : 13:32:00
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| Oh! OK .I got your point and which would be pain in the AZZ. |
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ahmad.osama
Posting Yak Master
183 Posts |
Posted - 2009-02-25 : 06:26:41
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quote:
Originally posted by sodeep
Oh! OK .I got your point and which would be pain in the AZZ.
absolutely  Regards,Ahmad Osama |
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differential backups