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Appendix B: The raid5 Command Line Interface
Low Watermark
Percentage of dirty cache pages that, when reached
during flush operations, will cause the SP to cease
flushing the cache.
Valid values are 0 through 100; the default is 50,
regardless of whether caching is enabled or disabled.
High Watermark
Percentage of dirty cache pages which, when reached
during flush operations, will cause the SP to cease
flushing the cache.
Valid values are 0 through 100; the setting must be
greater than the low watermark. The default is 75,
regardless of whether caching is enabled or disabled.
SP A Cache Pages
Number of cache pages currently owned by SP A
SP B Cache Pages
Number of cache pages currently owned by SP B
Unassigned Cache Pages Number of dirty cache pages not owned by A or B. This
can happen when a unit is broken and there are no disks
to which to flush the dirty pages
Read Hit Ratio
Percent of read requests to the SP that can be satisfied
from the cache without requiring disk access
Write Hit Ratio
Percent of write requests to the controller that can be
satisfied with the cache without requiring disk access
Prct Dirty Cache Pages
Percentage of cache pages that this SP owns that are
dirty
Prct Cache Pages Owned Percentage of cache pages owned by this controller
when pages from other SP are taken into account
Prct Read Flushes
Percentage of reads to SP that caused the cache to flush
a page(s)
Prct Write Flushes
Percentage of writes to SP that caused the cache to flush
a page(s)
Table B-3 (continued)
Output of raid5 getcache
Entry
Meaning