Changes between Version 2 and Version 3 of jazz/12-06-02

Timestamp:

Jun 3, 2012, 11:29:12 AM (12 years ago)

Author:

jazz

Comment:

--

jazz/12-06-02

@@ -43 +43 @@
 AIX vio ioo is a read ahead cache system to improve speed of transfers when doing sequential reads.
 }}}
-  * [參考五] [http://www.linuxpinguin.de/2011/01/performance-increase-through-bigger-readahead-buffers/ Performance increase through bigger readahead buffers] - 以下示範是把預設的 RA 由 256 提升到 1024
+  * [參考五] [http://www.linuxpinguin.de/2011/01/performance-increase-through-bigger-readahead-buffers/ Performance increase through bigger readahead buffers] - 以下示範是把預設的 RA 由 256 提升到 1024（注意是設定'''整顆硬碟'''，而非特定磁區）
+{{{
+The default value for the readahead buffer in linux 256, 
+so by increasing this to 1024 we can get a better read performance in sequential reads from the disks.
+To set this you need to do this for each disk (not partition) of your system. eg.:
+}}}
 {{{
 ~$ blockdev --report
@@ -50 +55 @@
 rw   256   512  4096       2048    497999151104   /dev/sda1
 rw   256   512  4096  972656640      2106589184   /dev/sda2
-~$ sudo blockdev --setra 1024 /dev/sda1
+~$ sudo blockdev --setra 1024 /dev/sda
 }}}