We use the subfile feature but not for vm's. And it does appear to still be limited to 2 gig. Someone from dev posted a long time ago that it was a limit due to the ms api that tsm uses to map the files in memory.
I have never seen any message that they were going to lift this limit. I had hope that tsm would support src depupe??? ----- Original Message ----- From: ADSM: Dist Stor Manager <ADSM-L@VM.MARIST.EDU> To: ADSM-L@VM.MARIST.EDU <ADSM-L@VM.MARIST.EDU> Sent: Thu Jun 25 10:13:48 2009 Subject: [ADSM-L] VMware image subfile backups We are exploring VMware backups here, and I ran across the following recommendation in IBM Redbook, "Deployment Guide Series: IBM TSM V5.5", which recommends using subfile backups to backup the VMware image files: >Incidentally, we use selective backup as opposed to incremental backup >with full >Virtual Machine images. We do so because when we use subfile backup, all the >subfile chunks can be retained for the same amount of time. full Virtual >Machine >backup works well with Tivoli Storage Manager adaptive differencing (subfile >backup) technology, which eliminates much of the backup overhead of taking >full >images at the client side, before they ever make it to the Tivoli Storage >Manager >server. This process facilitates very efficient backups both from a >client-processing perspective and from the perspective of overall storage >utilization on the Tivoli Storage Manager server. Only changed blocks are >transferred to the Tivoli Storage Manager server during subfile backup. They are suggesting using adaptive subfile backup to backup the VMware image files. Is anyone really doing this? Last I knew, subfile backups were limited to files less than 2GB in size, which would seem to me to make this recommendation of extremely limited usefulness. Thanks for any light-shedding. -- Paul Zarnowski Ph: 607-255-4757 Manager, Storage Services Fx: 607-255-8521 719 Rhodes Hall, Ithaca, NY 14853-3801 Em: p...@cornell.edu
