Drive
This section explains the installation conditions and installation rules for drives.
■
Types of Drives
The ETERNUS AF supports SAS SSDs with high-speed (12Gbit/s) interfaces.
SSDs are reliable drives with high performance. SSDs are used to store high performance databases and other
frequently accessed data.
Flash memory as a storage media provides better random access performance. Containing no motors or other
moving parts, they are highly resistant to impact.
The ETERNUS AF supports SSDs that have a high level wear leveling function. Note that if the expected total
write capacity is exceeded, the frequency of errors gradually increases, which may lead to a reduction in the
write performance. The ETERNUS AF has a function that shows the remaining capacity as a percentage (health)
in proportion to the expected total write capacity.
The number of rewrites may exceed the limit within the product warranty period if SSDs are used in a RAID1
configuration that has a high I/O access load.
The ETERNUS AF supports Value SSDs. They are available at a lower cost per capacity than conventional SSDs by
optimizing the guaranteed write endurance and the reserved space.
Note that the product's actual capacity of a Value SSD differs from the capacity that is displayed in ETERNUS Web
GUI and ETERNUS CLI. For example, 2.00TB is displayed for a 1.92TB Value SSD.
For ETERNUS AF, the supported drives vary depending on the model. For details, refer to the storage system
specifications in
.
■
Number of Installable Drives
The following table shows the number of installable drives.
Table 70
Number of Installable Drives
Type
AF150 S3
AF250 S3
AF650 S3
2.5" type controller enclosures
24
24
24
2.5" type drive enclosures
—
240
1,032
Number of installable drives
(max.)
24
264
1,056
For details on the number of required hot spares, refer to
"■ Number of Installable Hot Spares" (page 29)
4. Hardware Configurations
Installation Conditions and Installation Rules
178
Design Guide
Содержание ETERNUS AF S3 Series
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