5 6
2
3
4
2
7
1
1
1
AC Power switch
5
Manufacturing port (service only)
2
AC Power and Cooling Module (PCM)
6
SAS In port (SFF-8644)
3
Expansion module A
7
SAS Out port (SFF-8644)
4
Expansion module B (inverted)
Figure 14 Disk enclosure supporting either LFF or SFF disks
NOTE Disk enclosure characteristics:
l
Only HPE MSA qualified disks are supported by MSA 1060/2060/2062 disk enclosures.
l
Disk enclosures are equipped with two expansion modules.
l
Disk enclosures are equipped with two PCMs of the same type (both AC or both DC). The DC PCM is not available
with MSA 1060 disk enclosures.
l
The rear panel views of an LFF disk enclosure and SFF disk enclosure used with MSA 1060/2060/2062 controller
enclosures are identical.
l
The LFF disk enclosures and SFF disk enclosures can be intermixed, and are supported by MSA 1060/2060/2062
controller enclosures.
l
See the topic about connecting controller and disk enclosures for configuration limits when cabling disk enclosures.
For details about qualified disks and compatibility matrix information pertaining to MSA 1060/2060/2062 enclosures,
see
See also
"Front panel components" on page
. Refer to the bullet note entitled "Note Supported storage enclosure
configurations" for details pertaining to disk enclosures.
Cache
To enable faster data access from disk storage, the following types of caching are performed:
l
Write-back caching. The controller writes user data in the cache memory on the controller module, rather than
directly to the disks. Later, when the storage system is either idle or aging—and continuing to receive new I/O
data—the controller writes the data to the disks.
l
Read-ahead caching. The controller detects sequential access, reads ahead into the next sequence of data, and
stores the data in the read-ahead cache. Then, if the next read access is for cached data, the controller immediately
loads the data into the system memory, avoiding the latency of a disk access.
NOTE See the Storage Management Guide for more information about volume cache options.
Non-volatile memory
During a power loss or controller failure, data stored in cache is saved off to non-volatile memory (multi-channel eMMC
daughterboard in the controller module). The data is then written to disk after the issue is corrected. To protect against
18
Chapter 2
Components