The typical reason for this is that people are compressing at the client level and not realizing it. Check some of your larger "compressible" clients to see if the compression option is on. If so, it's compressing before it gets to the tape drive and you don't see the ratio there. If you have no network limitations, turn off compression at the client. (It can be forced off from the server with "upd n NODE comp=no" or "upd n * comp=no" for all nodes Tape hardware compression is faster and probably better
Regards, Shawn ________________________________________________ Shawn Drew Internet [email protected] Sent by: [email protected] 10/26/2009 11:56 PM Please respond to [email protected] To ADSM-L cc Subject [ADSM-L] Poor compression results Hi everyone, Please bear with me, I'm a small time school network admin :-) In short, the compression ratios I'm seeing appear to be quite poor. I'm looking for guidance on determining if 'thats all I'm going to get' due to hardware restrictions or if there is hope. The setup: We have a single instance of TSM (was 5.4, now 6.1) running on a single Win2k3 server, an IBM 3550 with 6GB ram. This is directly connected, no FC switch (thats coming) to a EMC CX300 SAN via 2GB FC. We run a IBM TS3200 4ru tape library with 2x 3580-TD3 drives (LTO3) connected on a single Ultra-320 SCSI card - Adaptec 29320ALP. Currently we pull from the clients (about 15 total) and spool it to the EMC SAN via a diskpool (500GB), the majority of clients are running 1gbit. Once that hits 50% utilisation, its migrated to tape. Each night we backup both the disk and tape pools to an offsite tape pool. All of this is done outside of business hours during exceptionally low utilisation times. Below is a sample of the various volumes we have. H:\TSMDATA\SERVER1\POOL S\DISK0.DSM DISK DISK 51.2 G 023335L3 TAPE LTO3 420.7 G 023336L3 TAPE LTO3 417.4 G 023337L3 TAPE LTO3 438.0 G OFF001L3 OFFSITETAPE LTO3 445.7 G OFF002L3 OFFSITETAPE LTO3 439.9 G OFF003L3 OFFSITETAPE LTO3 488.4 G I believe I have the config in TSM setup right.. tsm: SERVER1>q devcl Device Device Storage Device Format Est/Max Mount Class Access Pool Type Capacity Limit Name Strategy Count (MB) --------- ---------- ------- --------- ------ -------- ------ DISK Random 1 FILEDEV1 Sequential 1 FILE DRIVE 102,400.0 32 LTO1 Sequential 0 LTO ULTRIUMC 1 LTO3 Sequential 2 LTO DRIVE 409,600.0 2 tsm: SERVER1>q drive f=d Library Name: LIBRARY Drive Name: MT4.0.0.2 Device Type: LTO On-Line: Yes Read Formats: ULTRIUM3C,ULTRIUM3,ULTRIUM2C,ULTRIUM2,ULTRIUMC,ULTRIUM Write Formats: ULTRIUM3C,ULTRIUM3,ULTRIUM2C,ULTRIUM2 Element: 256 Drive State: LOADED Volume Name: 092394L3 Allocated to: WWN: Serial Number: 1210170739 Last Update by (administrator): ADMIN Last Update Date/Time: 05/05/2009 09:30:24 Cleaning Frequency (Gigabytes/ASNEEDED/NONE): NONE Library Name: LIBRARY Drive Name: MT5.0.0.2 Device Type: LTO On-Line: Yes Read Formats: ULTRIUM3C,ULTRIUM3,ULTRIUM2C,ULTRIUM2,ULTRIUMC,ULTRIUM Write Formats: ULTRIUM3C,ULTRIUM3,ULTRIUM2C,ULTRIUM2 Element: 257 Drive State: LOADED Volume Name: OFF029L3 Allocated to: WWN: Serial Number: 1210306202 Last Update by (administrator): ADMIN Last Update Date/Time: 05/05/2009 09:30:30 Cleaning Frequency (Gigabytes/ASNEEDED/NONE): NONE Given that a LARGE amount of our backups are SQL databases and transaction logs, I was expecting better than 1.075 to 1 compression ratio. My understanding that LTO3 likes to run at or about 80MB/s. Ultra320 will run up to 320MB/s. The slowest portion of our setup is the 2Gb/s FC connection into the SAN. Your thoughts would be greatly appreciated. Maybe I need to force the devclass to use compression rather than give it the option.. but I would assume compression is favoured over not? Regards, Jason Clarke ------------------ Network Manager Glen Waverley S.C. p 03 8805 6750 m 0418 145 318 e [email protected] Please consider the environment before printing this email. This message and any attachments (the "message") is intended solely for the addressees and is confidential. If you receive this message in error, please delete it and immediately notify the sender. Any use not in accord with its purpose, any dissemination or disclosure, either whole or partial, is prohibited except formal approval. The internet can not guarantee the integrity of this message. BNP PARIBAS (and its subsidiaries) shall (will) not therefore be liable for the message if modified. Please note that certain functions and services for BNP Paribas may be performed by BNP Paribas RCC, Inc.
