Need suggests on sizing logical volume for database (Oracle8i)

[Jessica Chou]

We have a volume group contains only one
logical volume encompass the whole disk,
which seems to be inappropriate for the use
of oracle. For example, a redo log file
should have saved in a different disk
from datafiles. (same as for two multiplex log files ...etc.) I acknowledged a logical volume is analogous to a partition, so may i reconfigure this volume group and make it constains several logical volume (e.g. 8)?

Thank you in advance.

Jessica

[Anthony Goonetilleke]

Yes if you don't have enough physical disks to split the files at least do it in different logical volumes. For example the oracle OFA structure or something of your own. For example you can instal oracle in something like /ora01 and your data files in /ora02 and indexes in /ora03 or somthing similar I hope you get the idea..

[Jessica Chou]

Thank you for your reply.
So, should I use lvreduce to first reduce the existing logical volume then take advantage of the freed out space to lvcreate
some new logical volumes?

Jess

[Stefan Farrelly]

You said it yourself, youve only got one disk and Oacle recommend seprating out to separate disks, so theres little point in going to the effort of creating multiple lvols when they will still be on the same disk.
If youve got OnlineJFS then the effort required to split into multiple lvols wont be so great, but if not you cant really lvreduce the current lvol, you may lose data if its on the part of the disk you are reducing, you will have to offload your data, destroy the lvol then recreate multiple lvols and reload your data; hardly worth it ?

[Richard Mertz]

I just usally make sure that I put database files in separate directories on an lvol so that when I get new disk, I can just mv the file and link the directory to where it is.