# Symmetrix Directors

The Symmetrix Directors attributes provide information about the disk directors on an EMC Symmetrix storage facility.

Cache Hit Pct Long Interval: The percentage of prefetched tracks found in cache during a long interval. A long interval is cache hits since IPL or STATUS CLEAR command.

Cache Hit Pct Short Interval: The percentage of prefetched tracks found in cache during a short interval. A short interval can be up to 10 minutes.

Cache Hits Long Interval: The count of cache hits since IPL or STATUS CLEAR command.

Cache Hits Short Interval: The count of cache hits during a short interval. A short interval can be up to 10 minutes.

Cache Misses Long: The number of cache misses during a long interval.

Cache Misses Short: The number of cache misses during a short interval.

Director Index: The ID of this director.

Director Number: Identifies the disk director.

Director Type: The type of director.

I/O Requests Long Interval: The number of I/O requests for a long interval.

I/O Requests Per Second Long Interval: The average number of I/O requests per second during a long interval. A long interval is since IPL or the STATUS CLEAR command.

I/O Requests Per Second Short Interval: The average number of I/O requests per second during a short interval. A short interval can be up to 10 minutes.

I/O Requests Short Interval: The number of I/O requests for a short interval.

I/Os Per Second Long Interval: The average number of I/O operations per second during a long interval. A long interval is since IPL or STATUS CLEAR command.

I/Os Per Second Short Interval: The average number of I/O operations per second during a short interval. A short interval can be up to 10 minutes.

Long Interval: A long measurement interval expressed as hours, minutes, and seconds.

Managed System: The SMS name of this system.

Prefetched Tracks Percent Used: The percentage of prefetched tracks used.

Serial Number Index: The eight low order characters of serial number which serve as the control unit index.

Short Interval: A short measurement interval expressed as hours, minutes, and seconds.

SSID Index: The SSID to which this director is attached.

SSID: The subsystem ID of the Symmetrix control unit controlling this disk director.

Time Stamp: Displays the date and time this data was collected from the virtual tape server (VTS).

Total CCW Chains: The total number of I/O requests handled by the director.

Total I/Os Long Interval: The total I/Os (reads and writes) for a long interval.

Total I/Os Short Interval: The total I/Os (reads and writes) for a short interval.

Total I/Os: The total number of I/Os.

Total Prefetch Cache Hits: The total number of prefetch cache hits.

Total Prefetch Tasks: The number of prefetch tasks.

Total Tracks Prefetched: The total number of prefetched tracks.

Total Write requests: Total write requests.

Unused Prefetch Tracks: The number of unused prefetch tracks.

Used Prefetch Tracks: The number of used prefetch tracks.

Write Pct Long Interval: The percentage of write commands during a long interval. The value is `(Write channel commands) / (Reads and writes)` A long interval is since IPL or STATUS CLEAR command.

Write Pct Short Interval: The percentage of write commands during a short interval. Write channel commands divided by reads and writes. A short interval can be up to 10 minutes.

Write Requests Long Interval: The count of write requests during a long interval.

Write Requests Short Interval: The count of write requests during a short interval.