-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello Kern,
the problem is not so much the risk of errors, but that btape (and correspondingly, Bacula) fails even the simplest of readback tests with block sizes above 128KB. dd works perfectly well with multi-megabyte blocks, both reading and writing. Here's the info I previously collected: btape cannot reliably handle anything larger than 128 KB (fails on reading, see below). However, when I read (using dd) the tape that btape supposedly has written _two_ files of 10000 blocks each (and then fails after reading 3616 of them!), dd reads read _each_ of btape-written 10000-block ``files'' as _three_ separate actual tape files (of 3616+3616+2768=10000 blocks). Note that this specific test was performed with a block size of 512KB (see Device definition from bacula-sd.conf, below). So, this might actually be a Bacula-specific problem after all. We see this behavior consistently on two different HP LTO-5 drives, on two different SAS HBAs (one using mpt2sas as driver, the other one with mvsas), and using two different SAS cables. If you need additional info, please let me know how to proceed. Many thanks in advance, Andreas *** TRY BTAPE TEST, WILL FAIL ON READBACK gundabad ~ # btape -c /etc/bacula/bacula-sd.conf /dev/nst0 Tape block granularity is 1024 bytes. btape: butil.c:290 Using device: "/dev/nst0" for writing. btape: btape.c:477 open device "LTO-4" (/dev/nst0): OK *test === Write, rewind, and re-read test === I'm going to write 10000 records and an EOF then write 10000 records and an EOF, then rewind, and re-read the data to verify that it is correct. This is an *essential* feature ... btape: btape.c:1157 Wrote 10000 blocks of 524188 bytes. btape: btape.c:609 Wrote 1 EOF to "LTO-4" (/dev/nst0) btape: btape.c:1173 Wrote 10000 blocks of 524188 bytes. btape: btape.c:609 Wrote 1 EOF to "LTO-4" (/dev/nst0) btape: btape.c:1215 Rewind OK. Got EOF on tape. btape: btape.c:1233 Read block 3617 failed! ERR=Success *q btape: smartall.c:404 Orphaned buffer: btape 280 bytes at 15e55e8 from jcr.c:362 *** NOW READ BTAPE-WRITTEN TAPE USING DD gundabad ~ # mt -f /dev/nst0 rewind gundabad ~ # dd if=/dev/nst0 of=/dev/null bs=512k 3616+0 records in 3616+0 records out 1895825408 bytes (1.9 GB) copied, 3.7062 s, 512 MB/s gundabad ~ # dd if=/dev/nst0 of=/dev/null bs=512k 3616+0 records in 3616+0 records out 1895825408 bytes (1.9 GB) copied, 3.7542 s, 505 MB/s gundabad ~ # dd if=/dev/nst0 of=/dev/null bs=512k 2768+0 records in 2768+0 records out 1451229184 bytes (1.5 GB) copied, 2.88829 s, 502 MB/s gundabad ~ # dd if=/dev/nst0 of=/dev/null bs=512k 3616+0 records in 3616+0 records out 1895825408 bytes (1.9 GB) copied, 3.75554 s, 505 MB/s gundabad ~ # dd if=/dev/nst0 of=/dev/null bs=512k 3616+0 records in 3616+0 records out 1895825408 bytes (1.9 GB) copied, 3.75338 s, 505 MB/s gundabad ~ # dd if=/dev/nst0 of=/dev/null bs=512k 2768+0 records in 2768+0 records out 1451229184 bytes (1.5 GB) copied, 2.88846 s, 502 MB/s gundabad ~ # dd if=/dev/nst0 of=/dev/null bs=512k 0+0 records in 0+0 records out 0 bytes (0 B) copied, 0.247548 s, 0.0 kB/s -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.14 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlI4XrkACgkQk5ta2EV7Dox5qQCeIAL+9E6K9w0L7gL2KIXCsRDZ mQ8AnAknUMOWpCpV8Vw2ZBMYRZ0JQ6IM =E1lA -----END PGP SIGNATURE----- ------------------------------------------------------------------------------ LIMITED TIME SALE - Full Year of Microsoft Training For Just $49.99! 1,500+ hours of tutorials including VisualStudio 2012, Windows 8, SharePoint 2013, SQL 2012, MVC 4, more. BEST VALUE: New Multi-Library Power Pack includes Mobile, Cloud, Java, and UX Design. Lowest price ever! Ends 9/20/13. http://pubads.g.doubleclick.net/gampad/clk?id=58041151&iu=/4140/ostg.clktrk _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
