Hello Ruth, You should specify "512 k" instead of "512 kb".
To try different blocksizes with your configuration you can use "btape test". The full test will check if the wringint and re-reading of the last block works. I would suggest you try if the default blocksize works.(which is valid if you do not specify a blocksize at all). Then, you can double the blocksize to see which blocksize still works and if it gives you more speed. For more info see: http://www.bareos.org/en/Whitepapers/articles/Speed_Tuning_of_Tape_Drives.html Best regards, Philipp On 01.09.2016 06:10, David Sherer wrote: > On Wednesday, August 31, 2016 at 3:02:52 PM UTC-5, Ruth Ivimey-Cook wrote: >> I have bareos backing up to two LTO tape drives, and occasionally see errors >> such as the following. This problem is not specific to a particular client. >> I don't think it's specific to a particular drive, though mostly it happens >> with the LTO3 rather than the LTO4. Howver The LTO3 gets more use... >> >> I'd really like a solution because these errors require manual intervention >> to fix, wasting my time and also hold up the backup process for everything. >> >> ... earlier messages >> 2016-08-31 19:40:56 helva-sd JobId 1088: Despooling elapsed time = >> 00:23:49, Transfer rate = 89.57 M Bytes/second >> 2016-08-31 19:40:56 helva-sd JobId 1088: Fatal error: spool.c:306 Fatal >> append error on device "LTO3TapeStorage" >> (/dev/tape/by-id/scsi-3500110a-nst): ERR=block.c:1003 Read error on fd=4 at >> file:blk 0:0 on device "LTO3TapeStorage" >> (/dev/tape/by-id/scsi-3500110a-nst). ERR=Cannot allocate memory. >> 2016-08-31 19:40:56 helva-sd JobId 1088: Fatal error: Re-read of last >> block: block numbers differ by more than one. >> Probable tape misconfiguration and data loss. Read block=0 Want block=178510. >> >> >> Director and Storage are on same machine. The job messages above were from a >> remote client but the data is spooled via SSD. Drive I/O typically achieves >> 90MB/s. >> >> The error messages suggest to me that the problem is not in fact with the >> tape drive but something else. Given the previous append error, I suspect >> the attempt to read the previous block is not in fact reading the previous >> block but the "current" failed one, somehow. >> >> If the message text is correct and it is a tape misconfiguration, what sorts >> of things might be wrong? >> >> Of course, I'm a complete novice at this. Can anyone help identify what is >> really happening? >> >> Might it be possible to modify the code to skip back several (e.g. 4) blocks >> and reread/verify them all, and then carry on writing (possibly on the next >> tape) from one after the last known 'good' block? >> >> Regards >> Ruth >> >> >> Config details: >> >> Intel i5-2500K at 3.3GHz with 8GB RAM, 16GB swap. >> One HP LTO3 tape drive connected using U320-SCSI on Symbios 53c1030 PCIe >> interface at 160MB/s. Firmware D26D <== drive involved in error above. >> One Quantum LTO4 tape drive connected using U320-SCSI on Symbios 53c1030 >> PCIe interface at 320MB/s. Firmware W53F <== connected to same scsi bus >> >> Ubuntu 16.04 LTS, kernel 4.4.0-34, very lightly loaded. >> Bareos installed from Bareos.org repo, version >> 16.3.1.1471011706.f4784a7-1304.1 >> Volume data spooling from Samsung SSD on SATA-II interface. >> >> SD config for the LTO3 drive: >> Device { >> Name = LTO3TapeStorage >> Drive Index = 1 >> Autochanger = no >> Archive Device = /dev/tape/by-id/scsi-3500110a-nst >> AutomaticMount = yes >> AlwaysOpen = yes >> Media Type = LTO3 >> RandomAccess = no >> RemovableMedia = yes >> Offline On Unmount = yes >> Spool Directory = /media/tapespool/LTO3 >> Maximum Block Size = 512kb >> Maximum File Size = 32gb >> Maximum Network Buffer Size = 65536 >> Maximum Concurrent Jobs = 1 >> } > > your block size is wrong. The tape block size should be 512b not 512kb. 512 > is small though you might want to try 1024b > -- Mit freundlichen Grüßen Philipp Storz philipp.st...@bareos.com Bareos GmbH & Co. KG Phone: +49 221 63 06 93-92 http://www.bareos.com Fax: +49 221 63 06 93-10 Sitz der Gesellschaft: Köln | Amtsgericht Köln: HRA 29646 Geschäftsführer: Stephan Dühr, M. Außendorf, J. Steffens, P. Storz, M. v. Wieringen -- You received this message because you are subscribed to the Google Groups "bareos-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to bareos-users+unsubscr...@googlegroups.com. To post to this group, send email to bareos-users@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
