vgcreate fails with VGRA error

[Juan Pablo Wagner_1]

Hello everybody.

I want to grow SAN space. The equipment has raid 1 and raid 5, i installed a new hard disk in the raid 5 , now the equipment has four disks in raid 5. My equipment can see the new space, but if i try to create the vg the equipment send me the message: "VGRA for the disk is to big for the specified parameters. Increase the exented size of , decrease max_PVs/max_LVs and try again".
vg01 51188 raid 1.
vg02 102380 raid 5.
vg03 75212 raid 5.
vg04 new space?.
My parameters are:
Maximum Physical Extents: 34999.
Maximum Logical Volumes: 255.
Maximum Physical Volumes: 16.
Physical Extent Size (Mbytes): [ 4 - .
My questions are:
If i modify the values it could affect the operation of the others vg that i have working?. And if want to increase the available space in the future, It is posible if i modify these parameters?. finally i must create 13 or 14 lvols with 10 gigas space. What new values suggest that i use?

Thanks

[A. Clay Stephenson]

The maximum number of physical extents (max_pe) and the size of a physical extent (pe_size) is set on a per VG basis so that the settings on your new VG have no effect on your existing VG's. If you are running 11.23 and up, there is a supported command (vgmodify) that will allow you to adjust these paramters after a VG has been created otherwise those sizes are fixed and cannot be changed without recreating the VG. There is no performance impact from choosing a larger pe_size so I would increate the pe_size to 16MiB and unless you actually think you will need 255 LVOL's reduce that to 32 or so.

[skt_skt]

here is settings we use

-p 255pv
-l 255(default)lv
-s 32MB PE size
-e 3264 PE

which allows me to use a disk of upto 100GB. And we dont prefer to use any disk/LUN whihc is more than 100GB on volume groups.

[Torsten.]

As you can read above, you can change the values in a patched 11.23 version or in 11.31.

see
man vgmodify

or run

vgmodify -t /dev/vg_name

[Juan Pablo Wagner_1]

one questions more. The value maximum physical extents change from 34999 to 3264 how affect the functionally of hard disk, and what functio has these parameter?


thanks

[Geoff Wild]

man vgcreate

That will give you details on the parameters...

What you set for 1 vg does not affect the other existing ones....it only affects the one you set the parameters on...

When I do my vgcreates, I do:

vgcreate -s 32 -p 64 -e 32768 /dev/vg01 /dev/dsk/c3t6d0 /dev/dsk/c28t6d0

Rgds...Geoff

[SKSingh_1]

Hi,

No effect.

as extent size is high level configuration at LVM level. whereas actual disk access paarameter on lower layer remains same.

this high level parameter will affect on somthing when you are going to stripe a LV. again using upto 32MB won't be any issue over performance.

[SKSingh_1]

Hi,

No effect.

as extent size is high level configuration at LVM level. whereas actual disk access paarameter on lower layer remains same.

this high level parameter will affect on somthing when you are going to stripe a LV. again using upto 32MB won't be any issue over performance.

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