migrate data on external disk array to another one in MC/SG environment : any gotcha's?

[Geert Swillens]

Hello,

I'm currently migrating VG's which reside on HP-XP512 array to XP12000 array. Since the VG limitations were not set properly, we opted to do backup, restore to VG_temp, export old VG settings, import in new, and rename to the original name. Upto this point, I only had standalone servers, and the procedure works fine, but now I'm facing production environment which is in MC/SG cluster (manual failover).

Does the export import on the active node keep all the settings as they were original? Is there anywhere in the cluster settings a trace of the physical volumes which make up the VG?

any comments are welcome, I know this is not the clearest of explanations, so I will do my best to provide as much detail as asked.

thanks
Geert

[Chan 007]

Geert,

As long as the VG name is different (other than the clustered VG), you don't have any problem.

My understanding is that you have some vgs (viz vg1, vg2 vg3) under cluster. whereas you are planning to creare vg4 for the restore perpose. This will not affect the cluster. If my understanding is incorrect please correct me.

Chan

[Luk Vandenbussche]

Geert,

You have make the following considerations

1) Create VG and LV on one node
2) deactivate VG on node one : vgchange -a n vgxx
3) export vg on node one
vgexport -p -m map.vgxx vgxx
4) copy map file to other node
5) import vg on other node
mkdir /dev/vgxx
mknod /dev/vgxx/group c 64 0x0Y0000 (Y=unique id)
vgimport -m map.vgxx vgxx /dev/dsk/cxtydz (give here all the physical volumes)
6) Modify the package config files for new VG name (if it is changed)
7) one one node
vgchange -c y vgxx
8) Start the package

[Geert Swillens]

chan,

in detail : I have vgsapPRO, vgmntPRO and vgdbPRO in cluster. I cannot add PV's because of too low vg limitations.

Now I create a vgsapPRO_temp, vgmntPRO_temp and vgdbPRO_temp on my new disks, with exactly the same filesystem structure, renamed to *_temp. I do a backup of all filesystems in vgsapPRO, vgmntPRO and vgdbPRO, and I restore them to their corresponding _temps. Then I do following :
export original volume group :
#vgexport -s -v -m /home/buxus/vgsapPRO.mapfile vgsapPRO

- export temporary volume group :

# vgexport -s -v -m /home/buxus/vgsapPRO_temp.mapfile vgsapPRO_temp

- import disks used by vgsapPRO_temp into vgsapPRO

# vgimport -s -v -m /home/buxus/vgsapPRO_temp.mapfile vgsapPPRO

- comment temporary entries in /etc/fstab for vgsapPRO_temp

- mount all filesystem of vgsapPRO existing in /etc/fstab

and the same for vgdbPRO and vgmntPRO.

that's the exact procedure

[Chan 007]

Hi,

Now I got you,

you must use -p (with this your vginfo will be flused out),

also if you have more disks do -f (this will create text file) that has disk info

#vgexport -p -s -v -m /home/buxus/vgsapPRO.mapfile -f vgsapPRO.txt vgsapPRO

ioscan -fCdisk

get the new disk info (c1t2d3 etc)

vgcreate & mknod

Now you should change your txt file with the new disk numbers & then vgimport (not export)
# vgexport -s -v -m /home/buxus/vgsapPRO_temp.mapfile -f vgsapPRO.txt vgsapPRO_temp


# vgchange -a y

do the same for other VGS

- comment temporary entries in /etc/fstab for vgsapPRO_temp

- mount all filesystem of vgsapPRO existing in /etc/fstab


Chan