Maximum Number Of Disks And Maximum Usable Capacity For Random And Sequential Optimization - Sun Microsystems StorEdge 3000 Series Installation, Operation And Service Manual

Note – Your array is preconfigured for Sequential Optimization. If Random
Optimization is most appropriate for your use, you will need to delete all of the
preconfigured logical drives, change the optimization mode, and then create new
logical drives.
The type of application the array is working with determines whether Random or
Sequential I/O should be applied. Video/imaging application I/O size can be 128,
256, 512 Kbyte, or up to 1 Mbyte, so the application reads and writes data to and
from the drive as large-block, sequential files. Database/transaction-processing
applications read and write data from the drive as small-block, randomly-accessed
files.
There are two limitations that apply to the optimization modes:
One optimization mode must be applied to all logical drives in an array.
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Once the optimization mode is selected and data written to logical drives, the
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only way to change the optimization mode is to back up all data to another
location, delete all logical configurations of drives, reconfigure the logical drive
with the new optimization mode, and reboot the array.
Note – The maximum allowable size of a logical drive optimized for Sequential I/O
is 2 Tbyte. The maximum allowable size of a logical drive optimized for Random
I/O is 512 Gbyte. When creating a logical drive that is greater than these limits, an
error message is displayed.
For more information about optimization modes, including how to change your
optimization, refer to the Sun StorEdge 3000 Family RAID Firmware User's Guide for
your array.
5.6.4.1 Maximum Number of Disks and Maximum Usable Capacity
for Random and Sequential Optimization
Your choice of Random or Sequential optimization affects the maximum number of
disks you can include in an array and the maximum usable capacity of a logical
drive. The following tables contain the maximum number of disks per logical drive
and the maximum usable capacity of a logical drive.
5-12 Sun StorEdge 3000 Family Installation, Operation, and Service Manual • March 2004