MemFS

quinta-feira, 29 de dezembro de 2011

MemFS

How to mount/create a "filesystem"

First of all you need to install "MemFS_B.11.31.03_HP-UX_B.11.31_IA_PA" (11.31) or "MemFS_mega-11iv2" product.
Check though swlist if you have installed in your system:

# swlist -l product | grep -i memfs

If you don't have this product installed in your system you can download it trough software.hp.

This FS is sometime used for temporary DBs when you need fast IO, remember if the server halt your data will be lose.

# mount -F memfs -o user=USER,group=GROUP,size=100mb,mode=775 /memfs1

"-F memfs" is a mandatory parameter, is recommended use in the least "-o size=100mb" or the size of your FS will be defined according your swap size.

This is an example of a fstab entry:
memfs /tempdbmem memfs size=100mb,user=USER,group=GROUP,mode=0775 0 2

Sar has a version that lets you do an analysis focused on memfs.
I tested this MemFS using as a tempdb for Sybase and the return is very good but I recommend read the full documentation before to apply in your environment.