Hello Bob, On Thu, 2010-11-18 at 16:09 -0500, Bob Hetzel wrote: > 1) Make sure all the firmwares are up to date: the 1068E card, the tape > drives, specifically. While you're at it, make sure the Adaptec card has > up to date firmware too.
Drives, Library, Adaptec cards have the most recent firmware; I'll look into the LSI-controller shortly. > 2) You might want to try this other setting too... > Maximum File Size = 3GB Bingo! I absolutely missed the point in the documentation about writing EOFs every X GB causing constant repositioning of the drives. With the default of Maximum File Size = 1GB, btape and bacula do not go faster than 60MB/s. I now tried several values (4, 6, 8, 12GB), and with 8GB I can reach up to 120MB/s with btape fill on both drives. Wow. Thank you! Where can I send the beer? Or a good scotch? :) > 3) Looking at your output, you only got a bit over 500GB. Are you testing > with an LTO-3 tape? (max uncompressed size of those is only 400GB, whereas > LTO-4 tapes fit 800GB uncompressed so you should have gotten much more on > the tape before it thought it hit the end) If so, my understanding is that > the tape drive will operate backward compatibly, including lowering the max > read and write speeds to the previous generation's. (I wrote the rest of the mail before playing with the maximum file size, so this is just FYI) Interesting. I just did another test with the second drive but the same tapes, reaching 62MB/s and filling the tape at 770G (see below); I suppose the tape simply wasn't rewound when I first did the test (I did some 'speed'-tests before that could explain it). The tapes are definitly LTO4. > 4) Also, writing to the tape is very CPU intensive. Is the system busy > doing something else? No, the system was otherwise completely idle (no VMs, no other bacula processes running, no DB). > Just a few shots in the dark there, hopefully one of them helps. Very much appreciated, thank you. > In addition, until you get everything working, you should probably not mess > with the default network buffer size. The manual has this to say about > that setting: > Maximum Network Buffer Size = bytes > where bytes specifies the initial network buffer size to use with the File > daemon. This size will be adjusted down if it is too large until it is > accepted by the OS. Please use care in setting this value since if it is > too large, it will be trimmed by 512 bytes until the OS is happy, which may > require a large number of system calls. The default value is 32,768 bytes. > The default size was chosen to be relatively large but not too big in the > case that you are transmitting data over Internet. It is clear that on a > high speed local network, you can increase this number and improve > performance. For example, some users have found that if you use a value of > 65,536 bytes they get five to ten times the throughput. Larger values for > most users don't seem to improve performance. If you are interested in > improving your backup speeds, this is definitely a place to experiment. You > will probably also want to make the corresponding change in each of your > File daemons conf files. Thanks for the pointer; I did it after desperatly trying random things a while ago; it is removed for now. -- kind regards, Lukas ------------------------------------------------------------------------------ Beautiful is writing same markup. Internet Explorer 9 supports standards for HTML5, CSS3, SVG 1.1, ECMAScript5, and DOM L2 & L3. Spend less time writing and rewriting code and more time creating great experiences on the web. Be a part of the beta today http://p.sf.net/sfu/msIE9-sfdev2dev _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
