Yep... it's possible to arrange a single-drive environment; it's highly dependent on the onsite person doing tape mounts on request, and organizing the tape pool to satisfy your retention requirements -- if you're lucky, get sufficient disk pool storage to allow either single-drive reclamation or copy-pool support.
I've had two different situations, we resolved them as follows: 1. Manual single-drive -- a file server with Exchange server; we configured it for Incremental forever (the file server node), daily incremental with weekly full for the Exchange; we installed admin client on the desktops of 2 or 3 onsite supervisors, so they would watch for tape mounts, and react accordingly. We used server-to-server across a WAN for the database backups; again, daily incremental, weekly full (on the weekend, when traffic was low). This is probably the worst scenario for trying to use TSM -- but, that's what we did; it was running for about a year when I left the account -- turned it over to centralized backup personnel, who continue the operation. This was a "test" to see how good or bad it would be to manage remotely; it was "okay", but one must always take initiative to monitor the onsite folks performing tape mounts. Rather than try to do reclamation, we did once-a-month "Full" backups (by changing the policyset to absolute for one cycle), which would cause older tapes to (ultimately) go to "Empty", since retention of Exchange was one-month, files was 30-45 days... poor man's "trick" reclamation. Since this was a DLT, we minimized tape thrashing by running both daily backups in close succession, using same media for all the data... used one tape per week, accumulating approx. 15 tapes total, as they recycled. Refreshed all new tapes once per year. Another reason this is not quite as cool as we'd like is it lacks copy-pool protection against media failure -- for case of a large restore request (as in a disk drive failure). I think, more likely, a simpler approach, would be better -- weekly-fulls might be better than the monthly-absolute -- in case of media failure, you'd still have another copy of all but the most recent week's data). 2. Single-drive library with 6 or 7 slots -- installed sufficient disk pool to handle single-drive reclamation, as per Admin. Guide; works fine, allowed 14-day PIT supporting one tape drive's worth of file-served data (approx. 65 GB in this case); that, plus diskpool used for storing primary copy (never migrated), tape slots used for two copy pools (one kept onsite, the other sent offsite) plus db backups. 14-days of PIT translates to approx. 1.7 x file-server-capacity (using 5% per day data change/add/delete, rule-of-thumb). This is the minimal, workable configuration for TSM (imho); minimum recommended configuration would be TWO tape drive library with sufficient slots to hold all backup data for desired number of versions, plus some slots for db backups & daily copy pool tapes... can I do daily incremental db-backups to a single output tape (appending each day's data)?!? Never did reclamation -- all unexpired backup data kept in disk pool, never migrated... eventually, MOVE DATA could be used to vacate disk pool to allow for single drive reclamation of the onsite copy pool. Hope all this helps! Regards, Don ----- Original Message ----- From: "Etienne Brodeur" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, April 22, 2002 7:28 AM Subject: Re: Single Drive Manual Library > I HAD a client like your describe, small sites (less than 40 GB > total storage) withan LTO 3580 tape drive. The problem is that you have > to do reclamation on the disks (since you only have one tape drive), now > with an LTO tape (100 to 200 GB depending of compression) that's a lot os > space to leave empty on the server. So my client decided to NOT use > reclamation. He routinely deleted the volumes manually to be able to > reuse them. To make sure that he had a full copy of his files I > configured a selective backup that took everything on his machines once > per week. I had to setup TSM to work like the good old days of four > incremental and then a full backup. > > As for the DB backups, he had to change the tape in his drive > (doing a dismount vol _volname_ first) manually before the schedule DB > backup at 10:00 AM (he didn't want to have to type the commands himself). > Then he loads the tapes for tonight checking to make sure there is enough > space on it. If there isn't enough space then he does a delete volume > _volname_ discarddata=yes. > > In other words it's pretty horrible. We added an old tape drive > he had lying around and use that for the DB backups which helped a little. > I guest if you have reclamation it would help a lot, but you still have > to manipulate the tapes a lot and check for free space on them before > using them. > > I have setup sites in collocation with small library 5-8 slots and > one drive and that works well as long as you have enough space on disks to > reclaim your volumes. > > If anyone as good way of functionning with a single tape drive let me > know! > > Etienne Brodeur > > > > > > Kolbeinn Josepsson <[EMAIL PROTECTED]> > Sent by: "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]> > 04/22/2002 09:51 AM > Please respond to "ADSM: Dist Stor Manager" > > > To: [EMAIL PROTECTED] > cc: > Subject: Single Drive Manual Library > > > Hi all there, > > Does anyone have experience using TSM with Single Drive Manual Library for > small sites? I think it is rather complicated to get those configuration > to > work without problems, I have not found any recommendations or samples in > Red Books or Tivoli Manuals. > > If anyone have found out a good working configuration for Single Drive > Manual Library installation, and like to share it with others, then kindly > reply with short description of how to do... > > Also any suggestions are welcome. > > > Thanks and regards, > Kolbeinn Josepsson > > NYHERJI HF. > BORGARTUN 37 > IS-105 REYKJAVIK > ICELAND
