NonStop Operations Guide for H-Series and J-Series RVUs

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Monitoring Disk Configuration and Performance
SeeFor information about
SCF Reference Manual for the Storage SubsystemChecking configuration information for disk devices
Monitoring disk block and cache statistics
Measure User’s GuideExamining system performance data with Measure
Identifying Disk Drive Problems
For recovery operations, refer to “Recovery Operations for Disk Drives ” (page 151).
Table 28 Possible Causes of Common Disk Drive Problems
Possible SymptomsProblems
Error 43 (unable to obtain disk space for file extent) occurs.
If the disk is full, an application might go down.
Disk is full or does not have enough space.
Disk free space is fragmented.
The storage subsystem generates an event message but the
application continues to run.
One disk in a mirrored pair is down.
Users report access problems, applications go down, and
the storage subsystem generates event messages.
An unmirrored disk is down, or both disks in a mirrored
pair are down.
Users report poor application performance.Performance problems occur due to path switches or a
cache size that is too small.
Output from SCF INFO DISK, BAD command indicates
unspared defective sectors.
Defective tracks or sectors exist.
Intm-errors-exceeded messageDisk errors exceed a certain limit.
Slow-IOs-threshold-exceeded messageSlow I/O operations exceed a certain limit.
SCSI Disk Drives Attached to NonStop NS-Series Systems
The most common disk drive problems on attached SCSI disk drives include:
• Space problems such as full disks or free-space fragmentation
• Stopped disks
• Performance problems
• Defective tracks or sectors
150 Disk Drives: Monitoring and Recovery