vgextend

[Wamaitha]

hello,-- this is what happens when you do this every year: i have pvcreated the disks and made a directory and node for the group;
i tried to vgextend all the disks that had a description of SYMMETRIX in ioscan; getting teh following message:

Volume Group configuration for /dev/vg01 has been saved in /etc/lvmconf/vg01.conf
root@abcd:/> vgextend /dev/vg01 /dev/dsk/c2t2d4
vgextend: Warning: Max_PE_per_PV for the volume group (1016) too small for this PV (209774).
Using only 1016 PEs from this physical volume.
Current path "/dev/dsk/c2t0d0" is an alternate link, skip.
Current path "/dev/dsk/c2t2d2" is an alternate link, skip.
Volume group "/dev/vg01" has been successfully extended.
Volume Group configuration for /dev/vg01 has been saved in /etc/lvmconf/vg01.conf
root@abcd:/> vgextend /dev/vg01 /dev/dsk/c2t2d5
vgextend: Warning: Max_PE_per_PV for the volume group (1016) too small for this PV (209774).
Using only 101vgextend /dev/vg01 /dev/dsk/c2t2d6
vgextend: Warning: Max_PE_per_PV for the volume group (1016) too small for this PV (209774).
Using only 1016 PEs from this physical volume.ip.
Current path "/dev/dsk/c2t0d0" is an alternate link, skip.
Current path "/dev/dsk/c2t2d2" is an alternate link, skip.
Current path "/dev/dsk/c2t2d4" is an alternate link, skip. /etc/lvmconf/vg01.conf
Current path "/dev/dsk/c2t2d5" is an alternate link, skip.
Volume group "/dev/vg01" has been successfully extended.
Volume Group configuration for /dev/vg01 has been saved in /etc/lvmconf/vg01.conf

any ideas.

ps: all i am trying to do is add a new volume group that will be made up of all teh disks that point to the disk. do i need to make a change to max PVs?

sorry for the 2 questions in one -- just getting confused.-- not good, though all part of learning process.

thanks on advance.

[Hasan Atasoy]

hi vamaitha ;

you are trying to add a big disk to a vg . but vg values are small for this disk.
you have 2 choices.
1. recreate the vg with larger parameters
vgcreate -p xx -s yy ( you need to backup and restore )
2. use smaller disks. but this time you will get problem max_pv parameter.
what is your pe size .
could you paste "vgdisplay vg01 "

Hasan.

[Wim Rombauts]

Could you show us the output of vgdisplay -v /dev/vg01 ?

It looks like the disk you are trying to add is bigger than what your volume configuration can handle.

If this is a new vg (but I don't see the vgcreate command) recreate the VG with different parameters.

If this is an existing VG, just ive with it thatit can't use the complete diosk capacity, or create a new, bigger VG on the new disk, migrate your data to the new VG, drop the old VG and add the old disks to the new VG.

[Adisuria Wangsadinata_1]

Hi Wamaitha,

When you create the VG, you need to make sure that the Max_PE can accomodate the next disk (if you would like to extend the VG).

See man page of vgcreate for more details :

-e max_pe

Set the maximum number of physical extents that can be allocated from any of the physical volumes in the volume group. The default value for max_pe is 1016. However, if the size of any physical volume exceeds 1016 times the pe_size, the default value for max_pe is adjusted to match the physical volume size. The maximum number of physical extents can be a value in the range 1 to 65535.

-p max_pv

Set the maximum number of physical volumes that the volume group is allowed to contain. The default value for max_pv is 16. The maximum number of physical volumes can be a value in the range 1 to 255.

Hope this information can help.

Regards,
AW.

[Wamaitha]

hello, with all the problems i was having i ended up deleting the volume group. it is a new group that i am creating -- it is disk connected to the sun -- i have 4x410G assigned to teh system --
to avoid the error message with the pvs what is the syntex so it that i do not get the pv message.

thank you

[Wamaitha]

is there a wayor formula to calculate number of pv you will need. or should i just go with what is recommended on my output?

root@abcd:/> vgextend /dev/vg01 /dev/dsk/c2t2d4
vgextend: Warning: Max_PE_per_PV for the volume group (1016) too small for this PV (209774).

also the following messages-- anyone know wht the mean?
Current path "/dev/dsk/c2t0d0" is an alternate link, skip.
Current path "/dev/dsk/c2t2d2" is an alternate link, skip.
Current path "/dev/dsk/c2t2d4" is an alternate link, skip.
Current path "/dev/dsk/c2t2d5" is an alternate link, skip.

[Wim Rombauts · Accepted solution]

You need vgcreate -e x -s y -p z
z : The maximum number of physical disks you ever want to include into this VG. You could set it to 4 right now, but if you think you me ever need to increase the VG, you can as well set it to 8 or 16 or so.
y : The extent size, your choice. Depends a little on the onderlying hardware architecture
x : Make sure x * y is equal to or bigger than 410G. For instance, if y : 4 (4 megabyte extent size, a value of 102400 of x would give you 409600 maximu disk usage or 400G (so this is a little too small).

My tip, make x large enough, so that you can later add disks with double the capacity of the current disks, or you may later have to conclude that you cannot extend your VG enough to handle the increased storage request.

Another thing, the extent size must be nig enough to get 1 extent map for the PV into 1 extent. If vgcreate complains that the maximum numbr of extents is too big, double the extent size and half the number of extents.

[Hasan Atasoy]

hi warmaitha ,

mkdir /dev/vgtest
mknod /dev/vg01/group c 64 0x0m0000 ( m should be a free number in groups )
vgcreate -s 32 -e 65535 /dev/vgtest /dev/dsk/c2t2d4

and lvcreate ..


Hasan.

[Wamaitha]

thanks