Dell PowerVault MD3200 Series, Руководство CLI

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Script Commands
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Segment Size
The size of a segment determines how many data blocks that the RAID
controller module writes on a single physical disk in a virtual disk before
writing data on the next physical disk. Each data block stores 512 bytes of
data. A data block is the smallest unit of storage. The size of a segment
determines how many data blocks that it contains. For example, an 8 KB
segment holds 16 data blocks. A 64 KB segment holds 128 data blocks.
When you enter a value for the segment size, the value is checked against the
supported values that are provided by the RAID controller module at run
time. If the value that you entered is not valid, the RAID controller module
returns a list of valid values. Using a single physical disk for a single request
leaves other physical disks available to simultaneously service other requests.
If the virtual disk is in an environment where a single user is transferring large
units of data (such as multimedia), performance is maximized when a single
data transfer request is serviced with a single data stripe. A data stripe is the
segment size that is multiplied by the number of physical disks in the disk
group that are used for data transfers. In this case, multiple physical disks are
used for the same request, but each physical disk is accessed only once.
For optimal performance in a multiuser database or file system storage
environment, set your segment size to minimize the number of physical disks
that are required to satisfy a data transfer request.
Security Type
The securityType parameter is valid for physical disks that are capable of self
encrypting disk (SED). With SED, the RAID controller module firmware can
create a key and activate the physical disk security feature. The physical disk
security feature encrypts data as the data is written to the physical disk and
decrypts the data as the data is read from the physical disk. Without the key
created by the RAID controller module, the data written to the physical disk
is inaccessible.
Before you can set the
securityType parameter to capable or enabled, you must
create a storage array security key. Use the create
storageArray
securityKey
command to create a storage array security key. The following
commands are related to the securtiy key:
•
create storageArray securityKey
•
set storageArray securityKey
book.book Page 127 Friday, March 4, 2011 10:45 AM