kern/50691: EOT detection in sa driver prevents mutli volume dump

Mon Apr 7 11:50:20 PDT 2003

>Number:         50691
>Category:       kern
>Synopsis:       EOT detection in sa driver prevents mutli volume dump
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Apr 07 11:50:16 PDT 2003
>Closed-Date:
>Last-Modified:
>Originator:     Lars Köller
>Release:        FreeBSD 4.8-RELEASE i386
>Organization:
Computing Center, University of Bielefeld, Germany
>Environment:
System: FreeBSD odie.koellers.net 4.8-RELEASE FreeBSD 4.8-RELEASE #29: Sun Apr 6 15:36:57 CEST 2003 root at odie.koellers.net:/usr/src/sys/compile/ODIE i386

Fresh source upgrade from 4.7-RELEASE-p3 to 4.8-RELEASE on March 6th 2003.

>Description:

When dumping a volume on an SCSI magnetic tape, a tape change request
leads to the abort of the dump process (dump ant tape on same machine):

root at odie:~/
129569 : dump -0ua /opt
  DUMP: Date of this level 0 dump: Mon Apr  7 14:16:21 2003
  DUMP: Date of last level 0 dump: the epoch
  DUMP: Dumping /dev/ccd1a (/opt) to /dev/nrsa0
  DUMP: mapping (Pass I) [regular files]
  DUMP: mapping (Pass II) [directories]
  DUMP: estimated 3659849 tape blocks.
  DUMP: dumping (Pass III) [directories]
  DUMP: dumping (Pass IV) [regular files]
  DUMP: 12.90% done, finished in 0:33
  DUMP: 19.75% done, finished in 0:40
  DUMP: 26.95% done, finished in 0:40
  DUMP: 34.42% done, finished in 0:38
  DUMP: 39.71% done, finished in 0:37
  DUMP: 45.12% done, finished in 0:36
  DUMP: 50.15% done, finished in 0:34
  DUMP: 53.43% done, finished in 0:34
  DUMP: 57.82% done, finished in 0:32
  DUMP: 61.61% done, finished in 0:31
  DUMP: 64.98% done, finished in 0:29
  DUMP: 70.55% done, finished in 0:25
  DUMP: 75.63% done, finished in 0:20
  DUMP: 82.06% done, finished in 0:15
  DUMP: End of tape detected
  DUMP: Closing /dev/nrsa0
  DUMP: Change Volumes: Mount volume #2
  DUMP: Is the new volume mounted and ready to go?: ("yes" or "no") yes
  DUMP: Volume 2 begins with blocks from inode 516537
  DUMP: EOT detected at start of the tape!
  DUMP: The ENTIRE dump is aborted.

The kernel reports:

(sa0:ahc0:0:4:0): WRITE FILEMARKS. CDB: 10 0 0 0 2 0
(sa0:ahc0:0:4:0): DATA PROTECT asc:30,0
(sa0:ahc0:0:4:0): Incompatible medium installed
(sa0:ahc0:0:4:0): failed to write terminating filemark(s)
(sa0:ahc0:0:4:0): tape is now frozen- use an OFFLINE, REWIND or MTEOM command to clear this state.

The first tape was a 4GB DDS2 tape the second a 2GB DDS1 here are the mt output
before the dump starts and during the change of the tape:

root at odie:~/
129570 : mt stat
Mode      Density              Blocksize      bpi      Compression
Current:  0x24:DDS-2           variable       61000    DCLZ
---------available modes---------
0:        0x24:DDS-2           variable       61000    DCLZ
1:        0x24:DDS-2           variable       61000    DCLZ
2:        0x24:DDS-2           variable       61000    DCLZ
3:        0x24:DDS-2           variable       61000    DCLZ
---------------------------------
Current Driver State: at rest.
---------------------------------
File Number: 6  Record Number: 0        Residual Count 0
root at odie:~/
129571 : mt off
root at odie:~/
129572 : mt stat
Mode      Density              Blocksize      bpi      Compression
Current:  0x13:X3B5/88-185A    variable       61000    DCLZ
---------available modes---------
0:        0x13:X3B5/88-185A    variable       61000    DCLZ
1:        0x13:X3B5/88-185A    variable       61000    DCLZ
2:        0x13:X3B5/88-185A    variable       61000    DCLZ
3:        0x13:X3B5/88-185A    variable       61000    DCLZ
---------------------------------
Current Driver State: at rest.
---------------------------------
File Number: 0  Record Number: 0        Residual Count 0
root at odie:~/
129573 : mt rew

At this point I enter the "yes" statement in the dump window.

Before entering yes the new tape was mounted and the "mt stat" and
"mt rew" succeeded. Befor the upgrade (from source) the exact same setup
worked well a day before.

Note: I notice a change of the behaviour of the tape driver somehow in October
2002. Till there a EOT of the tape was correct signaled by the driver during
writing. After there was only an error reportet and the nuber of bytes written:

Aug 24 23:57:21 door dattape: dattape: Write returned: -1 instead 1048576 Bytes. No space left on device
Aug 25 21:36:35 door dattape: dattape: Write returned: -1 instead 1048576 Bytes. No space left on device
Aug 25 23:54:19 door dattape: dattape: Write returned: -1 instead 1048576 Bytes. No space left on device
Aug 27 21:34:08 door dattape: dattape: Write returned: -1 instead 1048576 Bytes. No space left on device
Oct  6 21:48:50 door dattape: dattape: Write returned: -1 instead 1048576 Bytes. No space left on device
Oct  6 23:36:47 door dattape: dattape: Write returned: -1 instead 1048576 Bytes. No space left on device
Oct 21 21:37:13 door dattape: dattape: Write returned: 0 instead 1048576 Bytes. No such file or directory
Oct 27 21:32:50 door dattape: dattape: Write returned: 589824 instead 1048576 Bytes. No such file or directory
Oct 27 23:17:27 door dattape: dattape: Write returned: 65536 instead 1048576 Bytes. No such file or directory
Nov  4 00:25:39 door dattape: dattape: Write returned: 65536 instead 1048576 Bytes. No such file or directory
Nov  4 00:32:00 door dattape: dattape: Write returned: 65536 instead 1048576 Bytes. No such file or directory
Nov  4 07:37:18 door dattape: dattape: Write returned: 786432 instead 1048576 Bytes. No such file or directory
Nov 10 23:46:53 door dattape: dattape: Write returned: 589824 instead 1048576 Bytes. No such file or directory
Nov 12 21:16:44 door dattape: dattape: Write returned: 589824 instead 1048576 Bytes. No such file or directory

The logs are gerenrated by the same application without any change!

>How-To-Repeat:

Perform a dump of a lage filesystem on more than one tape.

>Fix:

Don't know
>Release-Note:
>Audit-Trail:
>Unformatted: