Physical extent size and informix raw space

[Luke Morgan]

Hi,

I am going to be adding a new volume group to an autoraid.
It will be used for chunks of raw space for an informix database.
I intend to add a new dbspace and use this volume group solely for that dbspace.

I have been advised to use 16mb physical extents when creating this VG.
All the other VGs on the system have 4mb physical extents.
Will the extent size have any effect on Informix?

Cheers
Luke

[Sridhar Bhaskarla · Accepted solution]

Hi Luke,

No. It will not have any effect on the performance of informix. Extent based allocation allows the data to be arranged in an efficient way.

-Sri

[Mark Greene_1]

Using larger extents will allow you to create a larger volume group. Data still moves on and off the disks in whatever the controller's IO block size, which is independant of the extent size.

mark

[Luke Morgan]

Thank you both.

Luke