| 105 | === 3.1.2. Enabling "Write Cache" with arcconf === |
| 106 | |
| 107 | Enabling this feature can lead to major performance improvments in write mode.[[BR]] |
| 108 | '''HOWEVER''', all data stored in cache will be lost if a power failure or a hard reboot occurs.[[BR]] |
| 109 | So, you're supposed to keep write cache disabled if your controller doesn't have any battery pack. |
| 110 | |
| 111 | {{{ |
| 112 | server:~# arcconf GETCONFIG 1 |
| 113 | [...] |
| 114 | Controller Battery Information |
| 115 | -------------------------------------------------------- |
| 116 | Status : Not Installed |
| 117 | [...] |
| 118 | Logical device number 0 |
| 119 | Logical device name : RAID1 |
| 120 | RAID level : 1 |
| 121 | Status of logical device : Optimal |
| 122 | Size : 953836 MB |
| 123 | Read-cache mode : Enabled |
| 124 | Write-cache mode : Disabled (write-through) |
| 125 | Write-cache setting : Disabled (write-through) |
| 126 | [...] |
| 127 | }}} |
| 128 | |
| 129 | So here is current config: No battery pack on the controller, and thus, write cache disabled.[[BR]] |
| 130 | But I want to enable it, this server doesn't store really useful data; only speed matters here... |
| 131 | |
| 132 | Let's enable write cache: |
| 133 | {{{ |
| 134 | server:~# arcconf SETCACHE 1 LOGICALDRIVE 0 wb |
| 135 | Controllers found: 1 |
| 136 | WARNING: Power failure without battery support will lead to data loss. |
| 137 | Do you wish to continue? |
| 138 | Press y, then ENTER to continue or press ENTER to abort: y |
| 139 | |
| 140 | |
| 141 | Command completed successfully. |
| 142 | }}} |
| 143 | |
| 144 | Here we go ! Let's check if it's really enabled, and then, reboot. |
| 145 | {{{ |
| 146 | server:~# arcconf GETCONFIG 1 |
| 147 | [...] |
| 148 | Logical device number 0 |
| 149 | Logical device name : RAID1 |
| 150 | RAID level : 1 |
| 151 | Status of logical device : Optimal |
| 152 | Size : 953836 MB |
| 153 | Read-cache mode : Enabled |
| 154 | Write-cache mode : Enabled (write-back) |
| 155 | Write-cache setting : Enabled (write-back) |
| 156 | }}} |
| 157 | |