Technical data

4–54 Troubleshooting
W Write-protection state. For disk drives, a W in this column indicates that the
device is hardware write-protected. This column is blank for units that
comprise other kinds of devices.
C Caching state of the device:
a = read, write-back, and read-ahead caching enabled
b = read and write-back caching enabled
c = read and read-ahead caching enabled
p = read-ahead caching enabled
r = read caching only
= caching disabled
KB/S Average amount of data transferred to and from the unit during the last
update interval in 1000-byte increments.
Rd% Percentage of data transferred between the host and the unit that were read
from the unit.
Wr% Percentage of data transferred between the host and the unit that were
written to the unit.
CM% Percentage of data transferred between the host and the unit that were
compared. A compare operation can accompany a read or a write operation,
so this column is not the sum of columns Rd% and Wr%.
HT% Cache-hit percentage for data transferred between the host and the unit.
PH% Partial cache-hit percentage for data transferred between the host and the
unit.
MS% Cache-miss percentage for data transferred between the host and the unit.
Purge Number of blocks purged from the cache during the last update interval.
Table 4–13 Unit Status Columns (Continued)
Column Contents