DD and TSM compression

[tsmuser10]

We have a new DD and currently getting 3X compression, after talking to EMC support they said it could be data bein compressed before it's sesnt/oracle DB....etc. My quesion is...on the windows side they have:
largecommbuffers yes
compression yes
compressalways no

Should compression be turned off ? won't that slow down the backup ?

THX

 

[moon-buddy]

When backing up data to Data Domain devices, compression should be turned OFF. This is to take advantage of DD's compression capabilities to the max.

 

[chad_small]

EMC explicity states NO compression should be used on data before it is sent to the Data Domain. It plays havoc with your block level analysis and will defeat the purpose of the DD since it cannot analyse like for like blocks.

 

[BrianV]

I have to agree with moon-buddy and Chad. I have compression off and I'm seeing 13x compression my DD880 and 30x compression on my DD890. I've even seen it hit as high as 40x.