We have some very large oracle databases. Most of these compress very well. We did test with and without client compression. The rule we used for best is the total elapsed time. These were going to disk pools. We always got better results with client compression than without. As an added benefit, our disk pools could be smaller and there was less bandwidth taken up on our network. Sounds like a win,win,win for us.
My two cents worth -- Phillip Ford Senior Software Specialist Corporate Computer Center Schering-Plough Corp. (901) 320-4462 (901) 320-4856 FAX [EMAIL PROTECTED] -----Original Message----- From: Kelly Lipp [mailto:[EMAIL PROTECTED]] Sent: Thursday, January 17, 2002 7:23 PM To: [EMAIL PROTECTED] Subject: Re: Software/Hardware compression? One of the reason folks consider compression is to reduce backup times on the client side. However, I have never seen a case where compressing on the client reduced the backup time. Never. Always longer. Always. I concur with Wanda's assessment: if you need the space in the disk pool, then perhaps compress (this is also handled automatically by migration so who cares!). Kelly J. Lipp Storage Solutions Specialists, Inc. PO Box 51313 Colorado Springs, CO 80949 [EMAIL PROTECTED] or [EMAIL PROTECTED] www.storsol.com or www.storserver.com (719)531-5926 Fax: (240)539-7175 -----Original Message----- From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED]]On Behalf Of Prather, Wanda Sent: Thursday, January 17, 2002 10:01 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 *************************************************************** This message and any attachments is solely for the intended recipient. If you are not the intended recipient, disclosure, copying, use, or distribution of the information included in this message is prohibited -- please immediately and permanently delete this message.
