Rasilient PixelStor 5000, Руководство пользователя

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Hardware Installation
PixelStor 5000 User Manual
Rev. 1, May 2013 4-44
Figure 4-27 Create VD
– Enter Parameters
3. Enter the size in Gigabytes (GB) from the available free space in the Disk Group
4. Select the cache policy for the Virtual Disk

Auto
– provides mirrored cache and write back policies while two controllers are present
and operational. Should one controller fail, or be removed the cache policy is switched to
write through. Default setting

Write Through
– passes data to the disk and cache simultaneously.

Write Back
– does not provide mirrored cache. Write Back stores data in battery
protected cache and writes to disks as cycles are available.
5. Select the read-ahead policy

Enable
– allows read ahead operations. The read-ahead logic adjusts for traffic patterns
to improve bandwidth. Default setting

Disable
– turns off read ahead operations. It may be desirable to disable read-ahead in
environments with highly random small block read and write operations.