Netbackup / LTO5 compression

[erikd]

Hi, I have netbackup 7.1 with a IBM LTO5 library attached. I got compression ticked in every policy but it seems that my tapes dosent really get filled up the way i want to. Can someone please explain why my lto5 tapes only get filled to aprox 1,5-1,6tb(maximum) and not more? A lto5 tape is a 1,5tb/3.0tb with compression.

Data compression = Yes on my ibmlibrary

So why dosent my tape get compressed more?

Is it because i have already done compression at software level? (i.e policy compression)

Thx

/Erik

[AmolB]

Check if compression is working for the policy

Refer to http://www.symantec.com/docs/TECH143934

[Zahid_Haseeb]

Franky Netbackup Compression is not good as Winzip/Winrar.

My experience

I took SQL backup with compression enabled and a 30GB data got backed up around 25GB but when I took Native SQL backup and compress it via Winzip/Winrar the size was around 10GB

[Mark_Solutions]

Hi Just to clarify things a little ..... netbackup compression is not great, but if you use it then the data is already compressed when you come to write it to tape As a result you won't get much more than native rates and practically no compression For best performance don't use netbackup compression - just let the drive do its own thing Hope this helps

[Marianne]

PLEASE don't use NetBackup compression if you don't have one these problems:

Network bandwidth
Client on 10Base-T network

Rather rely on the device hardware compression.

Compression rate depends on the type of data being backed up. Types of data that compress well and types of data that do not compress well is documentes in NBU Admin Guide I under the topic 'Compression attribute'. The disadvantage of using policy-level compression is also listed under this topic.

[erikd]

Thx for the input, ill check it.

[teiva-boy]

Erik,  You mentioned you have compression enabled already in the policy.  You should NOT use compression in both software and in hardware.  It's one or the other.  Tape compression is generally better than software.

Disable software compression in the policy, and don't bother again with enabling it if you have hardware that can do it.  

[Zahid_Haseeb]

Disable software compression in the policy, and don't bother again with enabling it if you have hardware that can do it. 

I did this as well but did not find as the compression of WinZip/WinRar