HP主机系统参数问题

Question

各位老大，最近在小机看到两个系统参数不知是干吗的，帮忙看一下
#kmtune后里面的两个
dmp_max_msecs           10000  -  10000                     
dmp_pathsw_bshift          10  -  10                        

就是这两个

Answer 1

主机上是不是有veritas的vxvm
看起来就是动态多路径的参数

Answer 2

dmp_pathswitch_blks_shift
The number of contiguous I/O blocks (expressed as an integer power of 2) that are sent along a DMP path to an Active/Active array before switching to the next available path.

The default value of this parameter is set to 10 so that 1024 blocks (1MB) of contiguous I/O are sent over a DMP path before switching. For intelligent disk arrays with internal data caches, better throughput may be obtained by increasing the value of this tunable. For example, for the HDS 9960 A/A array, the optimal value is between 15 and 17 for an I/O activity pattern that consists mostly of sequential reads or writes.

The DMP path that is used for a block is calculated as follows:

path = (block# >> dmp_pathswitch_blks_shift) % number of paths

………………………………………………………………………………………………………………

只能找到这一个，这两个都是关于veritas DMP的，用的比较少，v1上是dmp_pathsw_bshift，v2上是dmp_pathswitch_blks_shift。

Answer 3

您那两句话只是说这两个东西可以调，但还是不太明白是干什么的

Answer 4

谢谢老大，不过不知道为什么，我的google搜出来的结果为啥和你的不一样呢

Answer 5

dmp_max_msecs is used as a timeout variable which can be changed as tunable value. Resolution: Made dmp_max_sec a tunable which can be tuned via kmtune
kmtune dmp_max_msecs - Google 搜索 (18 November 2009)
http://www.google.cn/search?hl=z ... A2&aq=f&oq=

Answer 6

dmp_max_msecs is used as a timeout variable which can be
dmp_max_msecs - Google 搜索 (18 November 2009)
http://www.google.cn/search?hl=z ... A2&aq=f&oq=
http://forums13.itrc.hp.com/serv ... mp;threadId=1148028