options in vgcreate

[hi_5]

Creation of a 350G filesystem, do I need any special option when create a vg?
- EMC storage, created a 400G metavolume., present to the hp host as 1 lun..thanks for your help

[Steven E. Protter]

If the volume group is going to grow past 30 or so Gigabytes, take a look at the options for this

-e max_pe

Max it out so you can have lots of physical pe's

SEP

[Pete Randall]

You should look at the "-e max_pe" option and the "-s pe_size" options. Please take a look at the man page for vgcreate.


Pete

[Ross Zubritski]

There are no special switches for this. One word of caution however, if this 400GB vg is for Oracle or something other RDBMS your should at the very least split the space up to allow for a separate meta for archive logs as well as separate hypers for rollback segments. One big meta is certainly not adeviseable for a multitude of reasons.

Regards,
RZ

[hi_5]

I figured it out what I need to give in terms of number in achieving this.i will increase the pe size to 256M per physical extents, and uses the -e as 1367... if takes 256 * 1367 = 350000 M = 350G...
Thanks for your help...

[Stuart Abramson_2]

I think that whoever thought of the 400 GB MetaVolume has made a mistake.

Everyone's situation can be different, number of paths, number of DBs, size of DB, number of disks, size of disks, model EMC, raid level, etc, but in general one GIANT MV is not too flexible.

You are much better off with some number of smaller hypervolumes where you manage your assignment, as suggested above. Put the "dbf" files on one large set of HVs, put the indices on another and put the logs on a third. log access can be very high.

I have been using 8.6 GB HVs for some years now, but have heard of people moving to bigger HVs, like 16 GB and 32 GB, as disks and DBs get bigger.

At my last site EMC proposed some number of big "striped metavolumes" where 146 GB disks were sliced into 8 GB HVs and the 8 GB HVs were concatenated into big MetaVolumes. What it means is that all of your disk directors are hit at once....

[Geoff Wild]

We're going through a similiar process - creating 33 GB Striped Meta volumes on EMC 72 GB drives - but the metas span 8 physical drives - performance is great.

With this setup - it doen't matter where redo/data files are - cause they stripe across multiple disks - performance is better then having a 2 GB Redo volume on a single disk - because now - that same 2 GB is across 8 drives.

The only option is to make sure your PE size is big enough (default is 4 - so for 33 GB - you need 8).


Rgds...Geoff