Step 2: Recognizing A Failing Disk; I/O Errors In The System Log; Disk Failure Notification Messages From Diagnostics; Lvm Command Errors - HP -UX 11i Administrator's Manual

Step 2: Recognizing a Failing Disk

This section explains how to look for signs that one of your disks is having problems, and how to
determine which disk it is.

I/O Errors in the System Log

Often an error message in the system log file, /var/adm/syslog/syslog.log, is your first
indication of a disk problem. You might see the following error
Asynchronous write failed on LUN (dev=0x3000015)
IO details : blkno : 2345, sector no : 23
See the system log errors fully described in
Volume Groups" (page
disk.

Disk Failure Notification Messages from Diagnostics

If you have Event Monitoring Service (EMS) hardware monitors installed on your system, and you
enabled the disk monitor disk_em, a failing disk can trigger an event to the (EMS). Depending
on how you configured EMS, you might get an email message, a message in /var/adm/syslog/
syslog.log, or messages in another log file. EMS error messages identify a hardware problem,
what caused it, and what must be done to correct it. The following example is part of an error
message:
Event Time..........: Tue Oct 26 14:06:00 2004
Severity............: CRITICAL
Monitor.............: disk_em
Event #.............: 18
System..............: myhost
Summary:
Disk at hardware path 0/2/1/0.2.0 : Drive is not responding.
Description of Error:
The hardware did not respond to the request by the driver.
The I/O request was not completed.
Probable Cause / Recommended Action:
The I/O request that the monitor made to this device failed because the
device timed-out. Check cables, power supply, ensure the drive is powered ON,
and if needed contact your HP support representative to check the drive.
For more information on EMS, see the Diagnostics section on the http://docs.hp.com website

LVM Command Errors

Sometimes LVM commands, such as vgdisplay, return an error suggesting that a disk has
problems. For example:
#vgdisplay
...
--- Physical volumes ---
PV Name
PV Status
Total PE
Free PE
...
The physical volume status of unavailable indicates that LVM is having problems with the disk. You
can get the same status information from pvdisplay.
The next two examples are warnings from vgdisplay and vgchange indicating that LVM has
no contact with a disk:
#vgdisplay -v vg
vgdisplay: Warning: couldn't query physical volume "/dev/dsk/c0t3d0":
The specified path does not correspond to physical volume attached to
1 18 Troubleshooting LVM
163), where it shows how you map this type of error message to a specific
v | more
,"Matching Error Messages to Physical Disks and
/dev/dsk/c0t3d0
unavailable
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