HP P6000 - Manual (Page 90)

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Average Read Hit Latency —The average time it takes to complete a read request (from
initiation to information receipt) from the array cache memory.
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Total Read Miss Req/s —The total number of read requests (per second) that failed to
complete from the array cache memory and were completed from physical disks instead.
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Total Read Miss Data Rate —The total rate at which data is read from physical disks
because the data was not present in the array cache memory.
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Average Read Miss Latency —The average time it takes to complete a read request
(from initiation to information receipt) from the physical disks.
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Total Write Req/s —The total number of completed write requests per second to a virtual
disk that were received from all hosts. Write requests can include transfers from a source array
to this array for data replication and host data written to snapshot or snapclone volumes.
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Total Write Data Rate —The total rate at which data is written to the virtual disk by all
hosts, including transfers from the source array to the destination array.
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Average Write Latency —The average time it takes to complete a write request (from
initiation to receipt of write completion).
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Total Flush MB/s —The total rate at which data is written to physical storage. Data
replication data written to the destination volume is included in the flush statistics. Host writes
to snapshot and snapclone volumes are included in the flush statistics; however, data flow for
internal snapshot and snapclone normalization and copy-before-write activity is not included.
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Total Mirror MB/s —The total rate at which data moves across the mirror port in servicing
read and write requests to a virtual disk group. Write data is always copied through the mirror
port when cache mirroring is enabled for redundancy. The mirror data rate includes read
data from the owning controller that must be returned to the requesting host through the proxy
controller. Reported mirror traffic is always outbound from the referenced controller to the
other controller.
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Prefetch MB/s —The rate at which data is read from physical storage into cache in
anticipation of subsequent reads when a sequential read stream is detected. Data replication
initial copy data traffic for a replicated virtual disk is reported by the owning controller in the
source volume prefetch statistics.
HP EVA host connection
The HP EVA host connection object provides information for each HBA that has a connection to
an array.
The counters are:
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Queue Depth , the average number of outstanding requests from each host adapter.
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Busies , the number of host requests that are throttled by the array controller for each host
adapter when some internal array resource has reached a limitation.
HP EVA host port statistics
The EVA host port statistics object provides information about performance and data flow of
host-initiated activity on each array host port. Data replication traffic is not included in these
counters. Depending on the array model, there are either two ports per controller (four per controller
pair) or four host ports per controller (eight per controller pair).
The counters are:
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Read Req/s —The number of read requests (per second) completed from each host port.
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Read MB/s —The rate at which data is read from each host port.
90 Monitoring array performance using HP P6000 Performance Data Collector