Date: 03 Jun 2003 15:06:56 +0200 From: Kern Sibbald <kern@sibbald.com> To: mjacob@feral.com Cc: freebsd-scsi@freebsd.org Subject: Re: SCSI tape data loss Message-ID: <1054645616.13630.161.camel@rufus> In-Reply-To: <20030602131225.F71034@beppo> References: <3EDB31AB.16420.C8964B7D@localhost> <3EDB59A4.27599.C93270FB@localhost> <20030602110836.H71034@beppo> <20030602131225.F71034@beppo>
next in thread | previous in thread | raw e-mail | index | archive | help
Hello, Dan has now re-run our test of writing to two tapes. In this test, he told Bacula not to attempt to re-read the last block written, so Bacula wrote until -1 with errno=ENOSPC was returned, wrote two EOF marks then put up the next volume. The results were the same (more or less) 12 blocks of data were lost, which corresponds to the smaller size of the restored file that was split across two tapes. These 12 blocks were also at the end of the tape. During the restore, Bacula reported the following: 03-Jun-2003 05:01 undef-sd: RestoreFiles.2003-06-03_04.36.59 Error: Invalid block number. Expected 6060, got 6072 and in Bacula's database, Bacula indicates that blocks 0 to 6072 were written to the first tape. In fact, only blocks 0 to 6071 were written to the first tape -- I see that Bacula has included the failed block in its count, which is wrong, but this doesn't change the results at all though. Bottom line: Even when we eliminate the code that backs up and re-reads the last block, we still see the last 12 or 13 blocks being lost. They were written by the program but are not physically on the tape. Next step: Dan is now running a test where Bacula will stop writing on the first tape before the EOM is reached. Best regards, Kern
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?1054645616.13630.161.camel>