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?
> 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.
Do not you use something from the following things in bacula configuration?
UseVolumeOnce
Maximum Volume Jobs
Maximum Volume Bytes
Volume Use Duration
?
--
Rudolf Cejka <cejkar at fit.vutbr.cz> http://www.fit.vutbr.cz/~cejkar
Brno University of Technology, Faculty of Information Technology
Bozetechova 2, 612 66 Brno, Czech Republic
------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and
threat landscape has changed and how IT managers can respond. Discussions
will include endpoint security, mobile security and the latest in malware
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
_______________________________________________
Bacula-users mailing list
Bacula-users AT lists.sourceforge DOT net
https://lists.sourceforge.net/lists/listinfo/bacula-users
|
