We are using TSM and the HSM client to replace a system which used Unitree and Cam backup software. The system provides two major functions. One is server/workstation backup. We have that part working fairly well (ignoring the usual TSM headaches).
The second function, which has me scratching my head for answers (and begging all of you for advice), is a nearline storage capacity. Basically, we provide what looks like a huge disk farm (really disks migrating to tape libraries) that users can FTP files to/from for storage. The understanding with this system is that we provide no "backup" of user files in the nearline storage, meaning that if a user deletes a file, it's gone, and he can't get it back, or can't restore an older version of an existing file. We do want offsite copies for disaster recovery, so if the whole system burns up through no fault of the users, we can restore their current data. With the old Unitree system, all tape storage was in an STK 9310 silo with 9840 drives, managed by ACSLS. As data was migrated to tape, 2 copies were made, and one copy sent offsite on a daily basis. With TSM, we have added a 3584 LTO library, and want to use the LTO tapes for offsite storage (denser tapes means fewer cartridges to shuffle). We have it working fairly well for the regular TSM server/workstation backups: backups go to a disk pool which migrates to a 9840 storage pool; 9840 pool is regularly copied to an LTO copypool, and we use the TSM DRM facilities to handle tape movement between the LTO library and the vault. The nearline storage facility gets a little more complicated. Essentially, the users ftp to/from a machine running the TSM/HSM client (which happens to be the same one running the TSM server). The ftp users directory is a space-managed directory which migrates to a 9840 tape pool for onsite storage. Our initial setup was to back up the ftp users directory to an LTO pool to go offsite. But we seem to keep running into gotchas. DRM doesn't handle primary sequential storage pools, so it wouldn't move the backups of the ftp users stuff. So I thought instead of backing it up, let's just define an LTO copy pool, and copy the HSM primary tape pool to it. That would probably let us get copies of the HSM tapes offsite, but it appears that not everything in a space-managed directory gets migrated to tape, so those tapes alone would not be sufficient to recover from a disaster. The simplest option seems to be continuing our strategy of backing up the directory to an LTO pool, and then copying that to an LTO copy pool for DRM. But that doubles our tape usage. Does anybody see a reasonable solution to our problem? Have I done a reasonable job of explaining what the problem is? To summarize: we want to use the HSM client to provide nearline storage, and we want tapes offsite that will allow us to accurately restore that data if the onsite facilities are destroyed, and we would prefer to have not more than 2 copies (one onsite, one offsite) of the data. -- Matt Simpson -- OS/390 Support 219 McVey Hall -- (859) 257-2900 x300 University Of Kentucky, Lexington, KY 40506 <mailto:[EMAIL PROTECTED]> mainframe -- An obsolete device still used by thousands of obsolete companies serving billions of obsolete customers and making huge obsolete profits for their obsolete shareholders. And this year's run twice as fast as last year's.
