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wmarais_floodg8's avatar
wmarais_floodg8
Level 2
9 years ago

LTO-3 Hardware/Software Compression

Hi guys,

 

INFO:

Server: HP DL180 G6

TapeDrive: HP StorageWorks Ultrium 920 SAS

Software: Windows Server 2012 R2 / Backup Exec 15

 

Problem:

LTO-3 Tapes only have 400GB uncompressed storage, and the tape drive does not support LTO-4 (If I'm not mistaken)

The backups I am doing are 395GB and they fail because (media full)

 

I have tried to figure out how to setup hardware/software compression, without any success.... 

Can someone please explain to me how/where to configure the compression?

 

Thanks

15
Backing Up
Backup and Recovery
Backup Exec
Configuring
Tip-How to
Windows Server (2003-2008)
  • CraigV's avatar
    CraigV
    9 years ago

    Haven't seen anything outlining that LTO3 can't do hardware compression, and the easiest way to test this is to download HP Library and Tape Tools, stop the BE services and run the compression test. This will tell you whether or not the drive can do this.

    We used to get HW compression on 1/8 G2 autoloaders when doing this test on LTO3-based drives with no hassles.

    It might be that your data is expanding if it is already compressed which would result in less space being used on a tape.

    Thanks!

6 Replies

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  • pkh's avatar
    pkh
    Moderator
    9 years ago
    LTO3 tape drive cannot read/write LTO4 tapes. You need to use LTO3 tapes. LTO3 does not support hardware compression. You have to use software compression. Compression is set in your backup job.
  • wmarais_floodg8's avatar
    wmarais_floodg8
    Level 2
    9 years ago

    Hi @pkh

     

    I have figured out that much yes.. Thank you

     

    Even after setting "Software" on the backup job option it does not do any compression..

     

    Please have a look at attached screenshot and advise

     

    Thanks.

  • CraigV's avatar
    CraigV
    Moderator
    9 years ago

    Haven't seen anything outlining that LTO3 can't do hardware compression, and the easiest way to test this is to download HP Library and Tape Tools, stop the BE services and run the compression test. This will tell you whether or not the drive can do this.

    We used to get HW compression on 1/8 G2 autoloaders when doing this test on LTO3-based drives with no hassles.

    It might be that your data is expanding if it is already compressed which would result in less space being used on a tape.

    Thanks!

  • pkh's avatar
    pkh
    Moderator
    9 years ago
    The stats reported are correct. The data are already compressed when it is sent to the tape drive. To get a sense of what the congestion is like, check the joblog to see how much data your are backing up and how much ends up on the tape. For example, you backup 80GB and 60Gb ends up on the tape. This means that you have a compression ratio of 1.5
  • wmarais_floodg8's avatar
    wmarais_floodg8
    Level 2
    9 years ago

    My Backup job is running on 2 different server I have noticed that on the one it does compression 3,5:1 and the other 1,2:1

     

    So I am the one that was wrong here, it all is setup and working like it should.

    We are just going to look at the data that are being backed up, and make a decision from there on thank you for your help!!

  • pkh's avatar
    pkh
    Moderator
    9 years ago

    Ah!  Got my hardware compression and hardware encryption mixed up again!