> We are wanting to run four images Linux with TSM as the application. > In the TSM literature it states that we should have 12GB of real > storage for each image. Is this virtual mamory or do we need 12 times > 4 for 48 GB REAL memory to accomplish this scenerio? Has anyone tried > this before?
It's going to depend a lot on your TSM workload, principally the number of nodes, the proportion of backup to archive work, and your expiration policies. The docs are written primarily from a Unix/Windows perspective, so take them somewhat with a grain of salt, but the gotcha with TSM is database expiration processing. Memory utilization during database expire tasks (migration is another one) spikes like mad in that there's a lot of locking and table munging going on which needs two-phase commit semantics. If you have only a small number of nodes and you're keeping only a few versions, then 12G per instance is overkill by about a factor of 10. Ditto if your TSM workload is mostly archive transactions. If you have a very active environment, more than about 500 nodes, or lots of versions/complex storage policies, then you'll need every ounce of that 12G and it's still going to drive your paging system bonkers during expires. The chunk of XSTORE you've got will help soak up some of that, but you'll definitely know it when those TSM servers start doing stuff. You can also expect your Linux guests to start dipping into their swap disks as well, so make sure at least the first one (if not all) are VDISK. Also, as several people said, look at the layout of your log disks and make sure you have plenty to absorb a large server's file being essentially logged sequentially without having to worry about hunting for log space. TSM queues transactions in storage if they can't be logged to disk in a timely manner and that will also cause storage requirements to balloon. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
