TSM servers - AIX v5.3.4.1 AIX 5.1 (yes I know...unsupported....working to phase out and replace with Linux servers).
I am currently dealing with a strange issue relating to data compression levels (or the lack there-of) I am hoping someone can explain or point-out where to look. We originally had 4-3592E05 drives in our 3494 tape library. We just added 3-more. FWIW, these drives have the new "encryption" feature (we didn't ask for it.....were told we had to take it.....cost us $3,000 more). Ever since we added the new drives, I am noticing a drop in the compression I am achieving from these drives on the AIX TSM server that owns the library. Before these new drives were installed, I achieved 1.8TB on one cartridge owned by this server. I didn't do much 3592 usage since I simply didn't have the drives to share amongst 4-servers. Since these new drives have been put into use and I have agressively started migrating data from 3590K tapes, I am only seeing <600GB per cartridge. This is almost no compression at all. I did a complete removal and re-add of all AIX tape and TSM devices and bounced the TSM server. It is obviously seeing and using them, with no issues. All drives have the latest firmware, D3I1_A38. Nothing has changed with the DEVCLASS. All 3592's are using the same devclass. It is configured as 3592-2C. Scaled at 100%. No, I can't say that the lower compression is coming from the new drives, only. Any thoughts on what gives ? Why the change in compression ratio (this is a high-mix of various kinds of data. I should be getting at least 1TB vs my Notes systems which can't compress much and I get around 700-800GB per cartridge). ---------------------------------------------------- Zoltan Forray Virginia Commonwealth University Office of Technology Services University Computing Center e-mail: [EMAIL PROTECTED] voice: 804-828-4807
