On Tuesday 06 April 2010, Giel wrote: >Jon LaBadie wrote: >> Not necessarily "in turn", but several could be running at the same >> time depending on several config parameters. For example, you allow >> a max of 10 DLE's to be backing up at the same time with "inparallel >> 10". > >I had inparallel 10 set with flush-threshold-dumped and > flush-threshold-scheduled 25.I received dump failed errors "no holding > space" and device busy. > >> Potential danger here in number of tapes available. >> One run can use up to 10 tapes, one cycle up to 50 tapes, >> yet you only have 15 tapes in use. >> >> Perhaps you don't expect to use 10/run, but even at 2 per run >> you barely have enough for a single cycle. I fear you are going >> to be overwriting the only copy of needed data. > >I my main configuration I have changed to 15 tapes. > >> It is common to limit a holding disk's usage of available space. >> But it sounded like this 1.3TB raid was dedicated. Why not use >> it all. >> >> Regardless, you are only allowing 1TB to be used. Are any of >> your DLE's bigger than 1TB? They won't be able to use the HD. >> Are backups of several DLE being started and each reserving >> the space it needs thereby running the HD out of available >> space to reserve? > >I have assigned 200 GB for another set with single tape drive for backing > up /etc and /var/mail and other important directories on all our > machines. > >Gene Heskett wrote: >> If you have 1.6Tb available, which are you limiting it 1.0 Tb? >> I have a good sized disk as holding disk, and I have that set to "use >> -500Mb" meaning it will use all but 500 megs of a .6Tb partition just >> for my stuff here at home. Average total for 2 machines is about 30Gb so >> that fits nicely. >> >> Also, except for my /usr/movies/ directory, I have the dle's defined to >> not have more than 10Gb in any one dle. Obviously, when its time for a >> level 0 on movies, then everything else gets scheduled for about a level >> 2. I've done a few weddings and they are bulky in raw. >> >> You might have better results breaking up some of the bigger DLE's into >> smaller pieces. > >We have 11 really big databases with medical data no less than ~800G each > and 1TB for /home. each database is on separate DLE. > >As a final result on backup server there will be 2 NEO's with 4 LOT4 tape > drives plus 1 single LTO4 drive. so this holding space will be divide for > two main Backup sets and third with this single tapedrive. But now I just > want to get it working reliably with one set because secon NEO is doing > backup with our current backap server (netvault)
In which case I would do 2 things, 1, add enough more 1.5Tb drives to the holding disk array to bring it to where it can handle the inparallel setting, and/or 2, reduce inparallel to something that will fit in the holding disk array when all of them use the same holding disk simultaneously. I'm not fam with the LTO-4 drive, what is the capacity of one tape? I also concur with Jon LaBadie, you need to add another batch of tapes if you are to be able to use a dumpcycle effectively. If you have say 20Tb all told, then obviously either that tapes must be that big, or runtapes will be greater than one. Use of compression will help as that data is probably not well packed due to formatting, and this is yet another example where the use of the drives compression would _not_ be advantageous. When you use the drives compressor, amanda has no clue about how full the tape is because of the hardware compressors variable effectiveness. If you use gzip (I've had some problems with bzip2) in your 'dumptype', then amanda counts bytes at the output of gzip, and has a much more precise view of what remaining capacity that tape may have. And this brings up yet another gotcha. The state of the hardware compression switch is generally stored in an invisible to us mortals, hidden header on the tape. That means you can turn it off, and the drive, in the process of recognizing the tape when it is inserted, will silently turn it back on if the tape has this flag set. In order to fix this, you will have to rewind the tape, and without allowing the drive to move the tape from that rewound state, write a new label using the force option. That seems to be the only way to turn compression in the drive off and make it stick. gzip then can do its best, which is usually much better than the hardware can do. My own /home, with 3.3Gb of data in it, compressed to 33.4% of its original size for a level0 last night. >+---------------------------------------------------------------------- > >|This was sent by [email protected] via Backup Central. >|Forward SPAM to [email protected]. > >+---------------------------------------------------------------------- > -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) The recent proliferation of Nuclear Testing
