Need to migrate data from one storage to another.

[Vicha Upariputtipong]

Dear Sir,
My customer need to migrate data from old storage to new storage by using Brocade DMM. In the existing system, they are using LVM to manage the volumes. They have 14 PVs, 1 VG and 20 LVs which are on the old storage. Does anyone has any ideas how to migrate data by using Brocade DMM? Do I need to create disk layout to be the same as the existing on or not?
Thank you.
Regards,

[Alzhy · Accepted solution]

What is Brocade DMM? Is it a SAN based migration tool?

As far as data migration from one storage array to another, here are what enterprises usually do it.

Case I. (Inexperienced Admins/Storage Team)
Let the array vendor do it. Period.

Case II. (Experienced Admins)
Use LVM or VxVM Mirroring. Done right, the migration will NOT incur any downtime nor be disruptive.

If you are an experienced Admin, you should know Case II. Let us know if you want details on how Case II is done and what level of understanding do youhave with respect to LVM or VxVM and disks in general

[Jim Paulsen]

Agreed - Case II works well. We have done several that way - with nominal impact... regards...

[Vicha Upariputtipong]

Dear Nelson and Jim,
Thank you for your suggestions. Brocade DMM (Data Migration Manager) is a SAN based migration tool that work on LUN level. It will migrate data between LUN to LUN. I have heard that if I want to use LVM mirroring I need to pay for license and also I really concern about performance when doing data migration. There is 1.5TB of data and I will do offline data migration. The customer do not have VxVM installed on their host. They usually use LVM to manage disk on the host. If you don't mind please kindly provide me how to do data migration by using LVM mirroring.
Regards,

[Vicha Upariputtipong]

Dear Nelson and Jim,
One more question about migration performance via LVM mirroring. How fast have you guys migrated data by using LVM mirroring. I have only one day (24 hours) to migrate 1.5TB of data from existing storage to new storage. I am not sure that I can finish on time ot not.
Thank you.
Regards,

[Amar_Joshi]

LVM mirroring is transparent, you mirror the 2 volumes (one from the old storage and one from new storage). Speed of mirroring 2 volumes depends upon how fast link you have between and the old storage and new storage SAN (recommended 2 Gbps switch based links to both storages without ISLs) and how much load on the server/storage.

Once you have both the volumes mirrored, you can drop the old volume from the volume group and you have completed the transparent migration to new storage.

[whiz_kid]

you should hv mirror/ux license to perform an LVM mirroring to migrate the data into the new san.

the steps are simple :

a. i wud present luns from storage basis the size of each lvol(i assume that the IOPS load balancing is taken from storage side).

b. i wud pvcreate and vgextend to include the new luns into the volume group

c. i wd do a "lvextend -m 1 /dev/vgxx/lvol1 "

d. i wll check the mirroring progress "
e. i ll do a "lvreduce -m 0 /dev/vgxx/lvol " to remove old disks.

f. vgreduce old disk



f.