The EF3015 System Components
E F 3 0 1 5 S e t u p G u i d e ( R e v A )
9
1.3
EF3015 Controller Enclosure Rear Panel Components
SERVICE
1
0
CACHE
CLI
CLI
HOST
8G
2,4G
8G
2,4G
SERVICE
1
0
CACHE
CLI
CLI
HOST
8G
2,4G
8G
2,4G
6Gb/s
6Gb/s
1
3
2
4
6
7
9
11
10
12
(DC power supply unit (PSU) is
5
8
1
mutually exclusive to the AC model)
1 - AC power supplies
2 - Host interface ports (FC)
3 - CLI port (RS-232)
4 - CLI port (USB - Type B) [see Appendix D]
5 - Host port (USB - Type A; reserved for future use)
6 - Network port
7 - Service port (used by service personnel only)
8 - Disabled button (used by engineering/test only)
9 - Expansion port
10 - Controller module B
11 - DC Power supply (2) — (DC model only)
12 - DC Power switch
1.3.1
Controller Module Face Plate
SERVICE
1
0
CACHE
CLI
CLI
HOST
8G
2,4G
8G
2,4G
LINK
ACT
6Gb/s
1.4
Cache
To enable faster data access from disk storage, the following types of caching are performed:
• Write-back or write-through caching. The controller writes user data into the cache
memory in 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.
• Read-ahead caching. The controller detects sequential data access, reads ahead into the
next sequence of data — based upon settings — 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.
