On Mon, Jul 18, 2016 at 08:40:17AM +0900, Chaerin Kim wrote: > Hello. > > I heard Amanda can schedule backups automatically. > So I tried using this function. > But it doesn't work as expected. > > I set Amanda as follows. > - dumpcycle: 1 days > - runspercycle: 5 > - tapecycle: 8 tapes > - strategy of dumptype: standard (default) > - maxpromoteday: 10000 (default) > - 4 DLEs (1.5GB, 1GB, 1.5GB, 1GB) > > I registered amdump command in crontab and Amanda ran every 3 hours. > I expected that it is backed up with backup level 0000 for each DLEs first > time, and then the backup level will be changed 0111, 1011, 1101, 1110, ... > . > But the real result is that the backup level was changed 0000, 1101, 1101, > 1101, 1101, 0010, 1101, ... . > The backup level 0010 was appeared in 12 hours cycle. > > What should I do to get the result I expected? > What are the criteria of scheduling of Amanda? > The designers of amanda were thinking of backup schedules in terms of days and weeks, not 8 runs per day. I would be unsurprised to find some anomolies with frequent runs.
You also lied to amanda about runs per day, telling it there will be 5 runs when there were actually 8. I would expect it to get its scheduling messed up if I told it my amdumps were daily with a 1 wk cycle and then ran amdump twice a day skipping sunday. You have a common misconception that a dumpcycle of X means one full dump of each DLE in one dumpcycle. It means "at least" one full dump per dumpcycle. The dumpcycle is not a fixed calendar cycle, i.e. not Sunday to Saturday for a 1 wk cycle. It starts anew, individually, for each DLE as it gets its level 0. In your case whenever a DLE gets its level 0, it will get its next level 0 within the next 5 runs. Amanda determines its various dump levels trying to get a "balanced" size dump each run. In your scenario, 5GB of full dumps plus XGB of level 1's. Let's guess that might be 1GB of changed data a week giving a total of 6GB. To be balanced, those 6GB would be spread over 5 dumps (your runs per cycle) meaning about 1.2GB per run (assuming you didn't lie and really ran 8 dumps). At the start, or after any major change, don't expect amanda's schedule to stabilize until several dumpcycles have given it some history to work with. Jon -- Jon H. LaBadie [email protected] 11226 South Shore Rd. (703) 787-0688 (H) Reston, VA 20190 (703) 935-6720 (C)
