Steps to add extra mirror

[Geert Joosten]

Hi,
We have a vg with 12 disks: logical volumes are striped and mirrored over 6 disks on another 6 disks. We have another 6 disks which need to being used as 2nd mirror. Are the following steps the correct one and in the right order?
1. vgextend /dev/vg01 /dev/dsk/c6t?d0
2. add new pvg03 in /etc/lvmpvg with the 6 new disks
3. lvextend -m 2 /dev/vg01/lvdb01 pvg03

Can this be done while running or is single-user mode preferred?

Thanks in advance,
Geert.

[KapilRaj]

Procedure looks correct !

No need to get it into single user mod but it will be a better idea to avoid excessive I/O

Regds,

Kaps

[SureshKumar_2]

Hi Geert

yes, u can go ahead it is in right order.

This is will do..

For each and every lv u have to do lvextend
like,
lvextend -m 2 /dev/vg01/lv??? pvg03


regards

suresh

[G. Vrijhoeven]

Hi Geert,

Looks fine.
I just like to add
4. # vgcfgbackup /dev/vg01

Regards,

Gideon

[Bill Hassell · Accepted solution]

Just one note: unless you created the original volume group with a much larger -e max_pe and -s pe_size, there may not be enough extent slots to accomodate the vgextend. The volume must accomodate the extents for all 18 disks in order to use them, regardless of whether they are mirrored at all. If you get an error using vgextend that there are not enough PE's available, you'll have to rebuild the entire volume (backup, unmount all lvols, lvremove, vgreduce, vgremove -- or simply backup, unmount, vgchange -a y vg01, vgexport vg01). Then vgcreate the new vg01 -- to avoid a small extent limit in the future, override the extent count and PE size for future growth.