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Data Migration to new storage.

sardeshpande197
Level 4

Hi
I have VxVM3.5 and we are planning to migrate the data to new storage.
As per my knowledge we need to add newdisk to existing dg and then we need to do vxmirror i.e /usr/sbin/vxassist -g <dgname> mirror <volumename> alloc=newdisk1,newdisk2.

 we have multiple volumes in every DG i.e 20 volumes in every Diskgriup and once we add the disk to dg .Do we need to allocate the disk manually to different volmes.?
Do we need to have disk of same size tobe added into Diskgroup.?
I can see in my existing configuraiton that one disk is being used by multiple voumes.

Secondly,I need to ask storage team to provide storage for data migration so how to calculate how much disk(LUNS) required  and what should be their size to migrate the data from every volumes.

Thanks
Sukkrut S





1 ACCEPTED SOLUTION

Accepted Solutions

Gaurav_S
Moderator
Moderator
   VIP    Certified

check out this thread...

https://www-secure.symantec.com/connect/forums/seamless-veritas-volume-migration

To answer your questions:

Do we need to allocate the disk manually to different volmes.?
-- It is your choice, if you don't allocate manually, vxvm will pick disks on its own & mirror.... I would prefer to allocate here since we need new plexes to explicitly go on new disks from new storage...

Do we need to have disk of same size to be added into Diskgroup.?
-- again your choice, disks can be equal or bigger in size, they can't be smaller... for e.g if your current volume is a concat volume of 100GB made by 3 disks, you can get 1 single disk allocated by storage of 100GB & mirror with this...



Secondly,I need to ask storage team to provide storage for data migration so how to calculate how much disk(LUNS) required  and what should be their size to migrate the data from every volumes.

-- sum up size of all the volumes & you should get the current total usage.... additionally you can keep some extra storage available for scalability.... commands that may help here:

# df -h   or df -k
# vxprint -qthg <diskgroup>       (check the dm entries for each disk size)
# format                 (you can check the size of s2 on each disk)


Gaurav

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4 REPLIES 4

Gaurav_S
Moderator
Moderator
   VIP    Certified

check out this thread...

https://www-secure.symantec.com/connect/forums/seamless-veritas-volume-migration

To answer your questions:

Do we need to allocate the disk manually to different volmes.?
-- It is your choice, if you don't allocate manually, vxvm will pick disks on its own & mirror.... I would prefer to allocate here since we need new plexes to explicitly go on new disks from new storage...

Do we need to have disk of same size to be added into Diskgroup.?
-- again your choice, disks can be equal or bigger in size, they can't be smaller... for e.g if your current volume is a concat volume of 100GB made by 3 disks, you can get 1 single disk allocated by storage of 100GB & mirror with this...



Secondly,I need to ask storage team to provide storage for data migration so how to calculate how much disk(LUNS) required  and what should be their size to migrate the data from every volumes.

-- sum up size of all the volumes & you should get the current total usage.... additionally you can keep some extra storage available for scalability.... commands that may help here:

# df -h   or df -k
# vxprint -qthg <diskgroup>       (check the dm entries for each disk size)
# format                 (you can check the size of s2 on each disk)


Gaurav

sardeshpande197
Level 4
Hi Gaurav

Is it possible to mirror stripe set to concat one...

v  fopvol0802   -            ENABLED  ACTIVE   20971520 SELECT    fopvol0802-01 gen
pl fopvol0802-01 fopvol0802  ENABLED  ACTIVE   20974080 STRIPE    4/64     RW
sd oradg08d1m-02 fopvol0802-01 oradg08d1m 5243520 5243520 0/0     EMC1_152 ENA
sd oradg08d2m-02 fopvol0802-01 oradg08d2m 5243520 5243520 1/0     EMC1_126 ENA
sd oradg08d3m-02 fopvol0802-01 oradg08d3m 5243520 5243520 2/0     EMC1_124 ENA
sd oradg08d4m-02 fopvol0802-01 oradg08d4m 5243520 5243520 3/0     EMC1_120 ENA

************************************************

 
# /usr/sbin/vxassist -g oradg08 mirror stpvol0802 orad08vmax
vxvm:vxassist: ERROR: Cannot allocate space to mirror 204800 block volume


Thanks
Sukrut s

Marianne
Moderator
Moderator
Partner    VIP    Accredited Certified

Try to add 'layout=nostripe"

Extract from vxassist man page:
When adding a new plex to an existing volume, the default is stripe, if the volume already has one or more striped plexes, and is nostripe, otherwise.

Gaurav_S
Moderator
Moderator
   VIP    Certified
are you sure you want to mirror stripe to normal plex ? striped are usually designed for performance.....  what is purpose of that volume ?

If you want to mirror stripe to stripe you need equal no. of stripe sets to mirror...


Gaurav