Dell PowerVault MD3220 - Manual (Page 57)

Planning: MD3200 Series Storage Array Terms and Concepts 57
• Least path weight with subset (Windows operating systems only)—The
least queue depth with subset policy is also known as the least I/Os or least
requests policy. This policy routes the next I/O request to a data path that
has the least outstanding I/O requests queued. For this policy, an I/O
request is simply a command in the queue. The type of command or the
number of blocks that are associated with the command are not
considered. The least queue depth with subset policy treats large block
requests and small block requests equally. The data path selected is one of
the paths in the path group of the RAID controller module that owns the
virtual disk.
Monitoring MD3200 Series System Performance
You can use the Performance Monitor to select virtual disks and RAID
controller modules to monitor or to change the polling interval. Keep these
guidelines in mind when using the Performance Monitor:
• The Performance Monitor does not dynamically update its display if any
configuration changes occur while the window is open. You must close the
Performance Monitor window and reopen it for the changes to be
displayed.
• Using the Performance Monitor to retrieve performance data can affect
the normal storage array performance depending on the polling interval
that you set.
• If the storage array you are monitoring begins in or transitions to an
unresponsive state, an informational dialog is displayed. The dialog
informs you that the Performance Monitor cannot poll the storage array
for performance data.
To monitor the performance of the arrays:
1 Open MDSM and select the appropriate storage array.
2 Open the Array Management Window (AMW) for the selected storage
array
3 In the AMW, select Storage Array Monitor Performance.
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