NonStop NS-Series Operations Guide (H06.12+)

Table 10-3 Common Recovery Operations for Disk Drives (continued)
RecoveryProblem
To check for unspared defective sectors with SCF:-> INFO
DISK $*, BAD, SEL started, sub magneticTo check for
unspared defective sectors with DSAP at a TACL
prompt:> DSAP $*
• Recovery for DSAP is not needed.
• Recovery for DCOM: use the SCF INFO DISK, BAD
command on the affected disk to obtain the bad sector
address. Before restarting DCOM, perform the
CONTROL DISK, SPARE command.
For more information, see the Guardian Disk and Tape
Utilities Manual.
Unspared defective sectors
“Recovery Operations for a Nearly Full Database File”
(page 132)
Nearly full database file
Performance problems can have various causes, including
path switches or a cache size that is too small. For
information about disk load balancing and increasing
cache size, see the SCF Reference Manual for the Storage
Subsystem.
Performance problems
If both halves of your mirrored system volume become
corrupted, use an alternate system disk if one is available.
For how to create an alternate system disk, see the Integrity
NonStop NS-Series Planning Guide.
• For internal SCSI disk drives: if there is no alternate
system disk and you cannot load from the CONFBASE
file, you might be able to perform a tape load from a
system image tape (SIT) to restore the system image
files to the $SYSTEM disk (SYSnn and CSSnn
subvolumes). Then load that image into processor 0
or 1.
A tape load reinitializes the disk directory. The disk
directory is overlaid with the directory from the tape.
All files on that disk are destroyed. Perform a tape
load only with the advice of the Global Customer
Support Center or your service provider.
• For M8xxx disk drives: you cannot perform a tape load
from a SIT.
Corrupt $SYSTEM disk
• Internal SCSI disks: the Support and Service Library
describes replacing disk drives.
• M8xxx fibre channel disks: these disks are FRUs and
can be serviced or replaced only by HP-trained service
personnel.
Failed disk drives
Recovery Operations for a Down Disk or Down Disk Path
To restart a disk or disk path:
Recovery Operations for Disk Drives 131