Forum Discussion

bharrison's avatar
bharrison
Level 3
10 years ago

Differental Backups w/Modified Time does Full Backup

I recently switched our backups from using the archive bit to using the Modified time instead. The idea was that modified times are supposed to be faster than checking each archive bit. I've since run one Full backup using the Modified time settings, and now our differentials are all performing full backups each time they run. The Full and Differential jobs are both set to use time stamps(they are under the same parent job), but it seems like the Modified Time is being completely ignored.

The files are stored on a Hitachi NAS unit and shared as CIFs folders. A Backup Exec agent cannot be installed on it.I recieve an error each time this unit is backed up due to this(full, incremental, or diff), though the files backup successfully. Backups are direct to tape via fiber channel.  Can I not make use of modified times to backup this server, or do I need some additional configuration?

  • Typically, one cannot run Differential / Incremental backups of NAS's shares. Archive bit isn't possible since a remote agent isn't installed and modified time is also not possible, since NTFS Change Journal isn't available on the NAS.

    Alternative would be to use iSCSI and present the data from the NAS as LUNs so that it appears local to a server. Install the agent on that server and then Differential/Incremental backups will be possible.

  • Ok, that makes sense. I can do Incremental/Differential backups of the Hitachi by making use of the archive bit, I was just hoping to squeeze a bit more speed out of them. I've switched back over to the archive bit and backups are performing correctly as before. Thanks!

  • In fact we only officially support incremental or differential backup where a remote agent is installed.  

    Information in

    http://www.veritas.com/docs/000037777

     

     

  • Typically, one cannot run Differential / Incremental backups of NAS's shares. Archive bit isn't possible since a remote agent isn't installed and modified time is also not possible, since NTFS Change Journal isn't available on the NAS.

    Alternative would be to use iSCSI and present the data from the NAS as LUNs so that it appears local to a server. Install the agent on that server and then Differential/Incremental backups will be possible.