[solaris][veritas]請教幾個術語

chao_ping

剛剛開始再看veritas volume manager的一些資料，有些不太理解，請教：
DMP: Dynamic Multipathing: 究竟是什么含義？
Plex 對應的概念在IBM 的LVM里面對應于什么概念？

clu65

DMP: Dynamic Multipathing. It is just link physical links in HP-UX LVM.

The idea is that you provide two physical path to the same physical device(in this case it is hard drive). In case of one controller failer, it will automaticall go through another links.

SUN Microsystem has AP(Alternate Pathing) similar to DMP.

Plex is made of SD(sub disks). And Volume is consisted of one or more plexes. I guess Plex is just like \"sub-mirror\" in HP-UX LVM. I guess IBM LVM is similar to HP-UX LVM.

Hope this might help.

You can go to the HP website to find \"VERITAS Volume Manager3.1 Migration Guide.pdf\". It tells you the difference between LVM and Veritas VM.

Hope this might help.

chao_ping

謝謝。
另外一個問題：
vxfs feature寫到：
support for large file systems(up to 1 terabyte)
support for large files(up to 2 terabytes)

文件系統(tǒng)都只支持1Terabytes，為什么寫到文件支持2Terabytes？
奇怪。

clu65

That is correct. It just tell you the theoretical limit for file size and file system size. It did not make much sense to me either. But in reality, you create very few file system larger than 100GB because performance issue.