Big Volume Groups (mkvg)

[KOG]

Hi Folks,

I need advise here pls, basically the company has ordered a new pSeries server with 6 * 36 gb discs.

Ques is how best should I create vg with a disc of this size i.e. should I use the big volume group command mkvg -B when creating vg for oracledata vg with four 36 gb discs? I want to make sure I am creating vg with partitions in its optimise size and utilising all the space from four discs as I possibility can. If using big volume group command what should be the best optimised size for pp? 32mb?

Is this command correct? mkvg -B -t 32 (if 32 is best optimised size for pp for 36gb disc).

Any suggestions or advice would be greatly appreciated.

Thanking you all in advance.

Regards

Katherine

 

[mrn]

If its oracle I would at least be tempted to seperate oracle itself from the datafiles and indeed seperate the index files from the datafiles. If nothing else you will get some I/O improvement. I take it AIX 5.2 is installed, if so I'd go for Enhanced Journaled File System.

Disk1 - Root
Disk2 - OracleVG
Disk3 - OracleDataVG
Disk4 - OracleData2VG

But at the end of the day it's down to personel preference. Some people may be tempted to raid or mirror.


--
| Mike Nixon
| Unix Admin
|
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[KOG]

Hi Mike

I plan to allocate disk0 to rootvg and disk1-4 to oracledata vg and the sixth disk to backup vg.

What I wanted to know is what is the best optimised PP size for the oracledata vg if I am going to allocate four 36gb discs to this volume group. The oracle datafiles will be mapped across four disks - the size of the database is not large but reasonable size.

Regards

K

 

[bi]

I would just take the default for PP size when creating the volume group.

It's too bad your company didn't consult you when they got those big disks. Two smaller disks for the OS would have been a better configuration. I hope they realize the possible consequences of not having the OS mirrored.

 

[bjverzal]

By all means -

Make hdisk0 and hdisk1 mirrored for rootvg.

Make hdisk2-hdisk5 for Oracle.

The PP size has little to do with how efficient the space is allocated, based on your hdisk sizes.

There is no reason to use the -B option. That will actually make more overhead.

Beyond that, you are pretty free to do what you wish.

BV

 

[uptodate]

To answer the Big Volume Group question: A big volume group is the number of physical volumes that can be added into the volume group, which is 32, or if -B is used this limit is 128 physical volumes.

 

[KOG]

Many thanks to all of you who has responded to my query.

Much appreciated.

Regards

K