topic Re: dmesg error in Operating System - HP-UX

dmesg error

zhaogui — Tue, 28 May 2002 03:26:59 GMT

Hi,
When I type dmesg, I got the following, can anyone tell me why and which device is bc031000?

Thanks,

SCSI: Attempt to access partially open device -- dev: bc031000
SCSI: Attempt to access partially open device -- dev: bc031000
SCSI: Attempt to access partially open device -- dev: bc031000
SCSI: Attempt to access partially open device -- dev: bc031000

Re: dmesg error

MANOJ SRIVASTAVA — Tue, 28 May 2002 03:32:41 GMT

Hi

can really say it , do you have a SCSI connect EMC frame ?

What does the syslog say ? Does it point to any Physical volume or a vg ?

Manoj Srivastava

Re: dmesg error

S.K. Chan — Tue, 28 May 2002 03:55:26 GMT

The device bc031000 would be ..
bc=is in hex and converted to decimel it's 188 and that represent the character(raw) device. If you do ..
# lsdev | grep 188
==> you'll see that it's a "sdisk" with major number 31 and minor number 188
03=bus number
1=scsi id
0=LUN number
00=driver specific, in your case it doesn't apply.
Hence we're looking at c3t1d0.
As for the message "attempt to access partially .." what it could mean is that when the kernel SCSI driver is not getting any response from the character device c3t1d0 when it query it BUT it does not mean it's a hardware error. The best way to explain this is take an example of a CDROM device. If the CDROM does not have a CD in it and you run the command say ..
# diskinfo
the command will give you an error because there is no media in it.
Hence the error above will be recorded in syslog. In this case there is no hardware error, merely indication of some SCSI command not being able to be fulfilled.

To determine that you do not have any hardware problem with c3t1d0, run cstm to check if there is any error log, better still run "exerciser" in cstm to confirm this.
# cstm
cstm> map
cstm> sel dev
cstm> info
cstm> infolog

Re: dmesg error

T G Manikandan — Tue, 28 May 2002 04:12:33 GMT

//*

What do partially open device SCSI messages in syslog.log mean? DocId: AUSRCKBRC00000687 Updated: 4/13/00 9:19:43 PM

PROBLEM
Periodically on some systems you will see messages like the following appearing
in /var/adm/syslog/syslog.log:

Jan 11 16:06:01 hp1 vmunix: SCSI: Attempt to access partially open device --
dev: bc094000
Jan 11 16:06:01 hp1 vmunix: SCSI: Attempt to access partially open device --
dev: bc094000
Jan 11 16:06:01 hp1 vmunix: SCSI: Attempt to access partially open device --
dev: bc096000
RESOLUTION
The kernel SCSI driver when it opens a device sends the INQUIRY,
START_STOP_UNIT, TEST_UNIT_READY and READ_CAPACITY SCSI commands to start
the device and get the characteristics and the capacity of the device.

If any of the above SCSI commands fail and the device is a raw device the
kernel will print a message like the ones above. This is done so commands
like diskinfo and mediainit can still open devices even though they may not
be ready.

An example would be a CDROM drive without a CDROM in it. For the diskinfo
command some of the SCSI commands will fail because there is no media (e.g.
READ_CAPACITY cannot return the amount of data on the CDROM if there is no
CDROM in the drive) but the INQUIRY command will work (i.e. even if the
CDROM does not have disk in it it will still reply with information to an
INQUIRY command). The mount command will not cause these errors because
the kernel mounts the CDROM, no programs attempt to open the device file.

Disk arrays can also create these messages. Disk arrays can have luns created
that have no device associated with them. See Document A5469587 for
information about this message and EMC BCVs, other disk arrays can also
cause these messages to be seen.

The attempt to access partially open device messages typically do not
indicate any problems that need attention, unless the device being complained
about SHOULD have a real device associated with it. In that case since
the disk array is not reporting some of the information needed by HPUX
the problem would most likely reside in the array.

*//