Rorke Data Galaxy Aurora Series Configuration And System Integration Manual page 93

G A L A X Y ® A U R O U R A C O N F I G U R A T I O N A N D S Y S T E M I N T E G R A T I O N G U I D E
be emptying more often. If you make it too high, you risk having to wait for a
larger cache flush.
Maximum Write Back Requests Outstanding: Just as you can control how
many commands the read will buffer, you can also control the amount of
commands that the write will buffer. The default value of 8 is good for most
cases. Setting the value too low or too high may result in dropped frames on
capture because either you are not allowing the client computer to send
enough write commands, or are accepting too many. Setting the value too high
will waste RAM.
Number of Stripes in Each Write Back Request: This setting controls a limit
on the amount of cache to use for each write command from a client. The
default value is 8, which is 1MB. This is fine in most cases. Making the value
too low would limit the cache too much. Making it too high would probably just
waste RAM.
Percent of Cache Available to Non-Real-Time Writes: This applies to the
real-time users. You can actually dial-down the cache for writing for non-real-
time users. This value is a percentage. The default value of 50, indicates that
real-time users only get a maximum of 50% of the cache. Setting this value too
high would render this setting useless. Setting it lower would further limit the
cache for non-real-time users. Keep in mind, this setting only applies to non-
real-time users - see below for real-time users. Note that this setting applies
globally to all non-real-time users.
Percent of Cache Available to Real-Time Writes: This is the same as
above, but only applies to real-time users. The default value of 75 indicates
that a real-time user gets 75% of the cache for writes. Setting the value higher
could impact non-real-time users more. Setting it lower gives up some of the
cache to the non-real-time users. It's almost the opposite of above. Note that
this setting applies globally to all real-time users.
Max Data Rate of Non-Real-Time Requests (MB/SEC) 0 for no limit: This
allows you to limit the bandwidth of non-real-time users in megabytes per
second. It is used to free up bandwidth for real-time users as well. The value
entered here is in megabytes per second. The default value, 0, does not limit
the maximum data rate for non-real-time users.
Max Number of Non-Real-Time Requests: Another way of limiting non-real-
time users is to limit the amount of read/write commands they can send. Note
that this setting affects all non-real-time users. The default value is 4. Setting
the value lower would further limit non-real-time users. Setting it higher would
cache more requests.
Reconstruct in Advance of Drive Completion: If a drive isn't performing as
well as the rest, this option is used to base the data on the parity, instead of
the data returned from the drive. In many cases, this can compensate for a
slow drive. This option is disabled by default.
92 Section 3 Management