====== 64 Adaptech WriteBack設定 ======

===== arcconfig =====


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


===== 設定例 =====

LOGICALDRIVE に対して、WriteBack Enableにする。

==== 設定前 ====

<code>
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)   
</code>


==== 設定コマンド実行 ====

※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。

<code>
# /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:
</code>


==== 設定後 ====
<code>
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)
</code>


==== 性能 ====

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


{{tag>adaptech arcconf}}