On 09/26/2012 02:35 PM, Stephen Thompson wrote: > On 09/25/2012 02:29 PM, Cejka Rudolf wrote: >> Stephen Thompson wrote (2012/09/25): >>> The tape in question have only been used once or twice. >> >> Do you mean just one or two drive loads and unloads? >> > > Yes, I mean the tapes have only been in a drive once or twice, possibly > for a dozen sequential jobs while in the drive, but only in and out of > the drive once or twice. > > I have seen this 200-300Gb capacity on new tapes as well as used.
I think I pointed this out before, but I also have used and new tapes with 400-800Gb on them. It seems really hit or miss, though the tapes with 400Gb or less are probably a 1/3 of my tapes. The other 2/3 have above 400Gb. > > I see it in both my SL500 library as well as my C4 library, which is a > combined 4 LTO3 drives (2 in each library). > > >>> The library is a StorageTek whose SLConsole reports no media (or drive) >>> errors, though I will look into those linux-based tools. >> >> There are several types of errors, recoverable and non-recoverable, and >> I'm afraid that you see just non-recoverable, but it is too late to see >> them. >> >>> Our Sun/Oracle service engineer claims that our drives do not require >>> cleaning tapes. Does that sound legit? >> >> If you are interested, you can study >> http://www.tarconis.com/documentos/LTO_Cleaning_wp.pdf ;o) >> So in HP case, it is possible to agree. However, you still >> have to have atleast one cleaning cartridge prepared ;o) >> >>> Our throughput is pretty reasonable for our hardware -- we do use disk >>> staging and get something like 60Mb/s to tape. >> >> HP LTO-3 drive can slow down physical speed to 27 MB/s, IBM LTO-3 >> to 40 MB/s. Native speed is 80 MB/s, bot all these speeds are after >> compression. If you have 60 MB/s before compression and there are >> some places with somewhat better compression than 2:1, then you are not >> able to feed HP LTO-3. For IBM drive, it is suffucient to have places >> with just 2:1 to need repositions. >> >>> Lastly, the tapes that get 200 vs 800 are from the same batch of tapes, >>> same number of uses, and used by the same pair of SL500 drives. That's >>> primarily why I wondered if it could be data dependent (or a bacula bug). >> >> And what about the reason to switch to the next tape? Do you have something >> like this in your reports? >> >> 22-Sep 02:22 backup-sd JobId 74990: End of Volume "1" at 95:46412 on device >> "drive0" (/dev/nsa0). Write of 65536 bytes got 0. >> 22-Sep 02:22 backup-sd JobId 74990: Re-read of last block succeeded. >> 22-Sep 02:22 backup-sd JobId 74990: End of medium on Volume "1" >> Bytes=381,238,317,056 Blocks=5,817,238 at 22-Sep-2012 02:22. >> > > Here's an example of a tape that had one job and only wrote ~278Gb to > the tape: > > 10-Sep 10:08 sd-SL500 JobId 256773: Recycled volume "FB0095" on device > "SL500-Drive-1" (/dev/SL500-Drive-1), all previous data lost. > 10-Sep 10:08 sd-SL500 JobId 256773: New volume "FB0095" mounted on > device "SL500-Drive-1" (/dev/SL500-Drive-1) at 10-Sep-2012 10:08. > 10-Sep 13:02 sd-SL500 JobId 256773: End of Volume "FB0095" at 149:5906 > on device "SL500-Drive-1" (/dev/SL500-Drive-1). Write of 262144 bytes > got -1. > 10-Sep 13:02 sd-SL500 JobId 256773: Re-read of last block succeeded. > 10-Sep 13:02 sd-SL500 JobId 256773: End of medium on Volume "FB0095" > Bytes=299,532,813,312 Blocks=1,142,627 at 10-Sep-2012 13:02. > > >> Do not you use something from the following things in bacula configuration? >> UseVolumeOnce >> Maximum Volume Jobs >> Maximum Volume Bytes >> Volume Use Duration >> ? >> > > No, none of those are configured. > > > Stephen > -- Stephen Thompson Berkeley Seismological Laboratory step...@seismo.berkeley.edu 215 McCone Hall # 4760 404.538.7077 (phone) University of California, Berkeley 510.643.5811 (fax) Berkeley, CA 94720-4760 ------------------------------------------------------------------------------ How fast is your code? 3 out of 4 devs don\\\'t know how their code performs in production. Find out how slow your code is with AppDynamics Lite. http://ad.doubleclick.net/clk;262219672;13503038;z? http://info.appdynamics.com/FreeJavaPerformanceDownload.html _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
