Date: Sun, 14 Sep 2003 21:03:14 +0400 (MSD) From: Spartak Radchenko <spartak@aif.ru> To: FreeBSD-gnats-submit@FreeBSD.org Cc: re@FreeBSD.org Subject: kern/56871: dd can't write variable length data blocks to SCSI DDS streamer. Message-ID: <200309141703.h8EH3EWv000817@corwin.aif.ru> Resent-Message-ID: <200309141710.h8EHAG3A040471@freefall.freebsd.org>
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>Number: 56871 >Category: kern >Synopsis: dd can't write variable length data blocks to SCSI DDS streamer. >Confidential: no >Severity: serious >Priority: high >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Sun Sep 14 10:10:16 PDT 2003 >Closed-Date: >Last-Modified: >Originator: Spartak Radchenko >Release: FreeBSD 4.9-PRERELEASE i386 >Organization: Arguments & Facts Weekly >Environment: System: FreeBSD corwin.aif.ru 4.9-PRERELEASE FreeBSD 4.9-PRERELEASE #0: Sun Sep 14 18:44:54 MSD 2003 spartak@corwin.aif.ru:/usr/obj/usr/src/sys/corwin i386 >Description: dd can't write the last short data block to SCSI DDS streamer. Moreover, it can't write variable length records, only in multiples of 1024. This problem was introduced in RELENG_4 between Aug 14 and Sep 10 2003. >How-To-Repeat: corwin# dd if=/dev/zero ibs=1024 count=1 obs=1024 of=/dev/sa0 1+0 records in 1+0 records out 1024 bytes transferred in 0.001765 secs (580166 bytes/sec) corwin# 1024 bytes are written, all OK. corwin# dd if=/dev/zero ibs=1025 count=1 obs=1024 of=/dev/sa0 dd: /dev/sa0: Invalid argument 1+0 records in 1+0 records out 1024 bytes transferred in 0.004238 secs (241623 bytes/sec) corwin# The last byte from 1025 is lost. There is a message in /var/log/messages: Sep 14 20:39:52 corwin /kernel: (sa0:ahd1:0:0:0): Invalid request. Fixed block device requests must be a multiple of 1024 bytes >Fix: I don't know the fix for this problem. In some cases a simple workaround can be used: dd if=... of=/dev/sa0 obs=1024 conv=osync >Release-Note: >Audit-Trail: >Unformatted:
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