Forum Discussion

Arun_K's avatar
Arun_K
Level 6
12 years ago

vtl

https://www-secure.symantec.com/connect/forums/what-virtual-tape-library

 

I was reading this VTL discussion today.

 

I come across various queries.

Restore can be faster in disk so as in VTL...backup can be faster in disk so as in VTL ....disk can also be faulty.

I agree that a VTL should retsore a few files quicker than tape, but then again, so will a disk storage unit.

"Backups that use a VTL rarely fail because of a VTL failure. " -...  Disks can and do fail, hardware in general can fail.

 

So if all we are getting on disk,Then why this VTL term or software  has been created? I mean what is the use of this as we are getting all this things from disk.And on top of it ,on VTL backups are going on disk.....

7.1.x and Earlier
Backup and Recovery
NetBackup
Solaris
  • Marianne's avatar
    Marianne
    12 years ago

    I think this discussion has gone on for long enough now.

    The discussion that you referred to in your opening post says it all.

    There is really nothing more to add.

    The only reason why VTL was developed, was because no backup software could address disk as backup device in an efficient and intelligent manner.

    NBU introduced Advanced Disk and OST in version 6.5.

    Since then, I personally see no use for VTL.
    As Nicolai said - if you have been using them and they work for you - carry on.

    But we know that this discussion is purely theoretical, as we all know that you are using DataDomain with OST plugin.

    .Please close off this discussion by marking a Solution.

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  • Nicolai's avatar
    Nicolai
    Moderator
    12 years ago

    VTL was created to plug-in in a traditional tape based world. This was before OST, deduplication and advanced disk option arrived. In my view VTL has no justification today - using plain disk with the advanced disk option or Netbackup MSDP has outmaneuvered VTL's.

    If you have VTL around and they are doing the job well - then continue using them.

    If they need replacement - throw them out and invest in plain disk with MSDP or some sort of deduplication array like EMC Data Domain or Symanetec 5020/5030.

    Best Regards

    Nicolai

  • Arun_K's avatar
    Arun_K
    Level 6
    12 years ago

    ok.So at that time VTL was performing what is being performed by OST and advanced disk option today?

  • mph999's avatar
    mph999
    Level 6
    12 years ago

    Exactly, VTL provided a way to use disk before backup applications had the funtionality use disk in the way they do today.

    One good reason to use them is for testing.  Care has to be taken though as although they look like a tape drive they are not a tape drive and therefore don't replicate issues such as firmware issues.

    Martin

  • Arun_K's avatar
    Arun_K
    Level 6
    12 years ago

    so VTL was used when backup applications was not having the functionality to use disk.

    But in VTL,Background is disk only.

  • mph999's avatar
    mph999
    Level 6
    12 years ago

    VTL is based on disk yes, I am not sure why you asked this again, as the posts above, including your own have confirmed this.

    As far as NBU is concerned, it thinks it is a real library, as it has no way of understanding a 'VTL', but then of course, that is the whole idea, a VTL is meant to look like a real library.

    Martin

  • Nicolai's avatar
    Nicolai
    Moderator
    12 years ago

    A VTL emulate tape to create a abstraction layer from Netbackup and the backend VTL disks.

    I you think disk and SSD disk, the controller in front emulate whetever you're PC require to function. The PC does not know there is a SSD in the background. A VTL uses the same idea.

     

  • mph999's avatar
    mph999
    Level 6
    12 years ago

    "A VTL emulate tape to create a abstraction layer from Netbackup and the backend VTL disks"

    Blimey Nicolai, you are making me have to think ...

  • Marianne's avatar
    Marianne
    Level 6
    12 years ago

    I think this discussion has gone on for long enough now.

    The discussion that you referred to in your opening post says it all.

    There is really nothing more to add.

    The only reason why VTL was developed, was because no backup software could address disk as backup device in an efficient and intelligent manner.

    NBU introduced Advanced Disk and OST in version 6.5.

    Since then, I personally see no use for VTL.
    As Nicolai said - if you have been using them and they work for you - carry on.

    But we know that this discussion is purely theoretical, as we all know that you are using DataDomain with OST plugin.

    .Please close off this discussion by marking a Solution.