Full backup and incremental backup

[YM_user]

Hi,

    I want to know that full backup of VM machine strategy. If full backup of one VM once a week at 11:00pm, and incremental backup in every day 11:00pm. Both of them backup copy keep for 1 weeks. Will full backup be deleted and incremental backup cannot restore?

Regards,

YM user

[Colin_Weaver]

Assuming Backup to Disk:

The full backup cannnot be reclaimed (deleted) automatically  as long as a chain of incrementals linked to the full have not expired. You can do it manually but the pop-up will then warn you and confirm deletion of the incrementals as well

Also as a default, we will not allow you to delete the last complete backup chain for any individual resource until a new backup chain for the same resource exists (again can be manually overruled or you can change the default)

If backing up on tape:

If the tape containing the full is not overwrite protected (based on media set renetion and when the last write operation to the tape took place) then the full can be deleted because the whole tape was overwritten even if some incrementals exists on a different tape that relate to the full.

[pkh]

For disk backup sets, you might want to read my article below https://www-secure.symantec.com/connect/articles/when-backup-sets-are-deleted-under-dlm

[YM_user]

Hi pkh,

    Thanks for your information. If my plan set full backup at every Saturday 11:00pm and incremental backup at Mon-Fri 11:00pm. What is ideal plan for retention period for full backup and incremental backup (e.g. should later than backup time)?

Regards,

YM user

[VJware]

There is no 'ideal" retention plan since RPO & RTO differs for companies to companies.

As a safe practice, atleast one set of backup sets should be retained when the next chain runs.

[pkh]

You need to check with your bosses as to how long to retain your backup sets. The longer you keep your backup sets, the further back you can restore, but you will use more disk space. You have to balance to the two conflicting requirements

[YM_user]

Hi pkh, VJWare,

   Thanks for your reply. I think full backup keep 6.5 days or fewer is ok before next full backup start. Is previous full backup would not be expired which I set 160 hours (Around 6.5 days) until next full backup is completed? Also, how can I compress the backup size? I select "software" but no differential between previous backup size which select "None"

Regards,

YM user

[pkh]

The amount of compression is dependent on the data that you back up.  See my article below for an explanation.

https://www-secure.symantec.com/connect/articles/compression-short-explanation

[YM_user]

Is that different between retention period and keep for option? I cannot find retention period but only period keep for. If no backup on job, that means the backup set must be deleted according to the period I set. Retention will not delete until new backup overwrite.

[VJware]

Retention period is the same as Keep For option.

[YM_user]

Hi VJWare,

    How is good practce for keep the backup set longer if next backup plan is paused until next backup overwrite?

Regards,

YM user