IBM MegaRAID 8480 Benutzerhandbuch
A-4
Glossary of Terms and Abbreviations
Copyright © 2006-2007 by LSI Corporation. All rights reserved.
SAS device
Any device that conforms to the SAS standard and is attached to the
SAS bus by a SAS cable. This includes SAS storage adapters
(host adapters) and SAS peripherals.
SAS bus by a SAS cable. This includes SAS storage adapters
(host adapters) and SAS peripherals.
SATA
Acronym for Serial Advanced Technology Attachment. A physical storage
interface standard, SATA is a serial link that provides point-to-point
connections between devices. The thinner serial cables allow for better
airflow within the system and permit smaller chassis designs.
interface standard, SATA is a serial link that provides point-to-point
connections between devices. The thinner serial cables allow for better
airflow within the system and permit smaller chassis designs.
SMP
Acronym for Serial Management Protocol. SMP enables communicates
topology management information directly with an attached SAS
expander device. Each PHY on the controller can function as an SMP
initiator.
topology management information directly with an attached SAS
expander device. Each PHY on the controller can function as an SMP
initiator.
SSP
Acronym for Serial SCSI Protocol. SSP enables communication with
other SAS devices. Each PHY on the SAS controller can function as an
SSP initiator or SSP target.
other SAS devices. Each PHY on the SAS controller can function as an
SSP initiator or SSP target.
STP
Acronym for Serial Tunneling Protocol. STP enables communication with
a SATA II device through an attached expander. Each PHY on the SAS
controller can function as an STP initiator.
a SATA II device through an attached expander. Each PHY on the SAS
controller can function as an STP initiator.
stripe size
The total disk space consumed by a stripe not including a parity disk. For
example, consider a stripe that contains 64 Kbytes of disk space and has
16 Kbytes of data residing on each disk in the stripe. In this case, the
stripe size is 64 Kbytes and the stripe element size is 16 Kbytes. The
stripe depth is four (four physical disks in the stripe). You can specify
stripe sizes of 8 Kbytes, 16 Kbytes, 32 Kbytes, 64 Kbytes, or 128 Kbytes
for each virtual disk. A larger stripe size produces improved read
performance, especially if most of the reads are sequential. For mostly
random reads, select a smaller stripe size.
example, consider a stripe that contains 64 Kbytes of disk space and has
16 Kbytes of data residing on each disk in the stripe. In this case, the
stripe size is 64 Kbytes and the stripe element size is 16 Kbytes. The
stripe depth is four (four physical disks in the stripe). You can specify
stripe sizes of 8 Kbytes, 16 Kbytes, 32 Kbytes, 64 Kbytes, or 128 Kbytes
for each virtual disk. A larger stripe size produces improved read
performance, especially if most of the reads are sequential. For mostly
random reads, select a smaller stripe size.
striping
Disk striping writes data across two or more disks. Each stripe spans two
or more disks but consumes only a portion of each disk. Each disk,
therefore, may have several stripes. The amount of space consumed by
a stripe is the same on each disk included in the stripe. The portion of
a stripe that resides on a single disk is a stripe element. Striping by itself
does not provide data redundancy; striping in combination with parity
provides data redundancy.
or more disks but consumes only a portion of each disk. Each disk,
therefore, may have several stripes. The amount of space consumed by
a stripe is the same on each disk included in the stripe. The portion of
a stripe that resides on a single disk is a stripe element. Striping by itself
does not provide data redundancy; striping in combination with parity
provides data redundancy.