atom feed70 messages in org.freebsd.freebsd-scsiSCSI tape data loss
FromSent OnAttachments
Kern SibbaldJun 1, 2003 10:54 am 
Dan LangilleJun 1, 2003 11:32 am 
Justin T. GibbsJun 1, 2003 1:08 pm 
Kern SibbaldJun 1, 2003 2:44 pm 
Justin T. GibbsJun 1, 2003 3:39 pm 
Matthew JacobJun 1, 2003 5:00 pm 
Matthew JacobJun 1, 2003 5:13 pm 
Dan LangilleJun 1, 2003 6:58 pm 
Matthew JacobJun 1, 2003 7:03 pm 
Kern SibbaldJun 2, 2003 1:28 am 
Kern SibbaldJun 2, 2003 1:29 am 
Kern SibbaldJun 2, 2003 1:57 am 
Kern SibbaldJun 2, 2003 3:45 am 
Dan LangilleJun 2, 2003 4:28 am 
Matthew JacobJun 2, 2003 8:05 am 
Justin T. GibbsJun 2, 2003 8:10 am 
Dan LangilleJun 2, 2003 8:14 am 
Matthew JacobJun 2, 2003 8:21 am 
Kern SibbaldJun 2, 2003 8:27 am 
Dan LangilleJun 2, 2003 9:46 am 
Dan LangilleJun 2, 2003 11:05 am 
Matthew JacobJun 2, 2003 11:11 am 
Justin T. GibbsJun 2, 2003 11:49 am 
Dan LangilleJun 2, 2003 12:06 pm 
Justin T. GibbsJun 2, 2003 12:10 pm 
Matthew JacobJun 2, 2003 1:14 pm 
Dan LangilleJun 2, 2003 2:16 pm 
Matthew JacobJun 2, 2003 2:24 pm 
Kern SibbaldJun 2, 2003 2:46 pm 
Matthew JacobJun 2, 2003 2:55 pm 
Kern SibbaldJun 2, 2003 3:31 pm 
Carl ReisingerJun 2, 2003 3:44 pm 
Matthew JacobJun 2, 2003 3:44 pm 
Dan LangilleJun 2, 2003 6:37 pm 
Kern SibbaldJun 3, 2003 12:28 am 
Kern SibbaldJun 3, 2003 6:07 am 
Carl ReisingerJun 3, 2003 6:19 am 
Kern SibbaldJun 3, 2003 6:37 am 
Carl ReisingerJun 3, 2003 7:01 am 
Matthew JacobJun 3, 2003 7:34 am 
Justin T. GibbsJun 3, 2003 7:51 am 
Kern SibbaldJun 3, 2003 8:05 am 
Kern SibbaldJun 3, 2003 8:11 am 
Matthew JacobJun 3, 2003 9:03 am 
Dan LangilleJun 3, 2003 9:10 am 
Justin T. GibbsJun 3, 2003 9:24 am 
Kern SibbaldJun 3, 2003 9:40 am 
Justin T. GibbsJun 3, 2003 10:03 am 
Kern SibbaldJun 3, 2003 10:19 am 
Kern SibbaldJun 3, 2003 10:34 am 
Matthew JacobJun 3, 2003 11:00 am 
Matthew JacobJun 3, 2003 11:16 am 
Matthew JacobJun 3, 2003 11:39 am 
Justin T. GibbsJun 3, 2003 12:12 pm 
Dan LangilleJun 3, 2003 12:43 pm 
Matthew JacobJun 3, 2003 12:46 pm 
Kern SibbaldJun 3, 2003 1:05 pm 
PostMaster GeneralJun 3, 2003 2:21 pm 
Kern SibbaldJun 4, 2003 12:20 am 
Matthew JacobJun 4, 2003 7:51 am 
Kern SibbaldJun 4, 2003 9:51 am 
Kern SibbaldJun 6, 2003 7:38 am 
Dan LangilleJun 6, 2003 8:59 am 
Matthew JacobJun 6, 2003 11:50 am 
Dan LangilleJun 20, 2003 6:17 pm 
Dan LangilleJul 1, 2003 5:07 pm 
Matthew JacobJul 1, 2003 11:11 pm 
Michael L. SquiresAug 25, 2003 4:16 am 
Dan LangilleAug 25, 2003 9:13 am 
Michael L. SquiresAug 27, 2003 5:27 am 
Subject:SCSI tape data loss
From:Kern Sibbald (ke@sibbald.com)
Date:Jun 3, 2003 8:11:56 am
List:org.freebsd.freebsd-scsi

On Tue, 2003-06-03 at 16:51, Justin T. Gibbs wrote:

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.

Bacula is supposed to start the process of a tape change as soon as the amount written is less than what you intended to write.

This is exactly what it does. *Every* time the requested write size does not agree with the returned value, Bacula gives up on the tape. My last email has the code that does that.

My email above was not very clear because I was telling you what happened in the particular case of loss of data (the -1 and errno=0 or errno=ENOSPC I don't know which). As noted here, Bacula *will* stop writing if the driver returns a short block (assuming my code isn't broken), but I have never seen that case on FreeBSD.

Ignoring the short write and waiting until you hit ENOSPC guarantees you will hit PEOM, since the LEOM is only reported once. The tape driver expects that you know what you are doing if you go on writing.

The only additional writing Bacula does (unless I am missing something) is the two EOF marks.