WOW ! be careful on the "slow down" statement... NOT THE CASE !!!!!!!!! Actually with a big enough client it will greatly speed things up ! We have an SAP environment with a 2.7 TB data base, we back it up in less than 18 hours using client compression if we didn't use client compression it would take 66 hours ! (based on 42 GB/hr ie. flooded fast ethernet) This is a Sun E10K with 64 processors (30 of which are bound to individual backup tasks) going to an IBM S70 TSM server with a diskpool large enough to hold one complete backup cycle. Oh, that is using a 100 MB/sec fast ethernet over which we push 42 GB/hr when we use a GB link we see 56 GB/hr and can back it up in less than 13 hours...
So by using client compression we SPEED THING UP and it runs in 1/5th the time ;-) Dwight -----Original Message----- From: Prather, Wanda [mailto:[EMAIL PROTECTED]] Sent: Thursday, January 17, 2002 11:01 AM To: [EMAIL PROTECTED] Subject: Re: Software/Hardware compression? It's not that bad, and not that big a deal. If you look around, you can find individual files that will expand due to compressing a second time (and it doesn't matter whether it's hardware or software compression the second time). But I've done testing with 3490 & 9840 technology, and if you are backing up a lot of generic systems like Windows and Unix file servers and print servers, overall I wouldn't worry about it. You won't get much ADDITIONAL compression the second time; probably 5-10% at most, but overall it's not likely to hurt you either. If you are backing up a system that contains a large application of MOSTLY compressed files (say a web server that stores zillions of compressed graphics files) you might have reason to be concerned and do some testing on that system before turning on TSM software compression. In general: TSM software compression will slow down the throughput for Backup and Restore on the client end. If you have LOTS of clients, so you need to save space in your disk pool, then use compression on the client. If you are sending over a slow link, then use compression on the client. If you have enough space in your disk pool and no bottleneck in your network, don't use compression on the client. If you have a client with an unusual application that has much pre-compressed data, test before you decide. -----Original Message----- From: Jason Stoessler [mailto:[EMAIL PROTECTED]] Sent: Thursday, January 17, 2002 11:21 AM To: [EMAIL PROTECTED] Subject: Software/Hardware compression? Hi All, I know in other products that you can not run software compression and hardware compression concurrently. I have been told that it results in the files reverting to an almost uncompressed state. What I need is to know if the same applies to TSM. My company are thinking of purchasing TSM so if anyone knows of an official statement from IBM/Tivoli that I can be referred to that would be appreciated. The software platform will be Solaris and the autochanger is an STK L700 with 9840 fibre drives TSM 4.2.1.7. Jason Stoessler Guardian iT
