# /usr/StorMan/arcconf SETCACHE

 Usage: SETCACHE <Controller#> LOGICALDRIVE <LogicalDrive#> <logical mode> [noprompt] [nologs]
 Usage: SETCACHE <Controller#> DEVICE <Channel# ID#> <physical mode> [nologs]

LOGICALDRIVE に対して、WriteBack Enableにする。

Logical device number 1
   Logical device name                      : ARRAY2
   RAID level                               : 10
   Status of logical device                 : Optimal
   Size                                     : 6673398 MB
   Stripe-unit size                         : 256 KB
   Read-cache mode                          : Enabled
   MaxCache preferred read cache setting    : Enabled
   MaxCache read cache setting              : Enabled
   Write-cache mode                         : Disabled (write-through)
   Write-cache setting                      : Disabled (write-through)   

※キャッシュバッテリが搭載されてないものだと、WARNINGが出る。

# /usr/StorMan/arcconf SETCACHE 1 LOGICALDRIVE 1 wb
Controllers found: 1
WARNING: Power failure without battery/ZMM support will lead to data loss.
Do you wish to continue?
Press y, then ENTER to continue or press ENTER to abort:

Logical device number 1
   Logical device name                      : ARRAY2
   RAID level                               : 10
   Status of logical device                 : Optimal
   Size                                     : 6673398 MB
   Stripe-unit size                         : 256 KB
   Read-cache mode                          : Enabled
   MaxCache preferred read cache setting    : Enabled
   MaxCache read cache setting              : Enabled
   Write-cache mode                         : Enabled (write-back)
   Write-cache setting                      : Enabled (write-back)

WriteBack Disabled

# dbench -t 10 4
Throughput 154.849 MB/sec  4 clients  4 procs  max_latency=119.115 ms

WriteBack Enabled

# dbench -t 10 4
Throughput 1432.61 MB/sec  4 clients  4 procs  max_latency=15.367 ms