Migrating a SUN server from one storage array to another

[kothur]

Hi All,
We are migrating a few SUN servers running solaris 8, 9 and 10 from the Hitachi Storage to EMC CX700 storage array. Veritas 3.5 and 4.1 are running on these servers. Our plan is to attach both the storage arrays to the sun server and create mirrors and then remove the old storage(Hitachi). I am new to VxVM and would like to know if anybody has any procedures for this migration. I would also appreciate if somebody could give me a detailed explanation of how I can find the existing disks on Hitachi from solaris, create the mirrors on EMC and then delete the disks from Hitachi.

Thanks

 

[Annihilannic]

Here's a rough outline off the top of my head, others may correct/improve on this. I'm assuming that you already know how to present the storage to the server and make it visible at the OS level. I'm also assuming a relatively simple VxVM configuration; if you are using Dirty Region Logging (DRLs) and/or Data Change Objects (DCOs) there will be additional steps to migrate them to the new storage.

1) Initialise the disks:

vxdisk init cNtNdN [ privlen=Nm ] (or vxdisksetup -i cNtNdN [ privlen=Nm ] on v3.5)

You may want to increase the private region length from the default to, say, 10m to accommodate future disk group growth as the defaults in pre-5.0 versions are not very large.

2) Add them to the appropriate disk group(s):

vxdg -g diskgroup adddisk newdisk1=cNtNdN newdisk2=cNtNdN ...

3) Mirror the volume(s) on to the new disks:

vxassist -g diskgroup mirror volume newdisk1 newdisk2 ...

If the existing volumes are, say, 4-way stripes, then of course you will need to supply a multiple of 4 newdisks on that command-line. I'm presume the existing volumes are unmirrored - if they are already mirrored within the Hitachi storage then you may need additional options to ensure you get the desired layout.

4) Identify the Hitachi plex (i.e. mirror) names using vxprint -g diskgroup volume, and then remove it using vxplex -g diskgroup -o rm dis plex-NN to both disassociate it from the original volume, and remove it completely.

5) Once the Hitachi disks are free of volumes, remove the disks from the disk group:

vxdg -g diskgroup rm olddisk1 olddisk2 ...

6) Optionally, if you want to be tidy, uninitialise the disks using vxdisk destroy cNtNdN (or vxdiskunsetup for 3.5).

Annihilannic.

 

[kothur]

Hi Annihilannic,
Thanks for the response and the detailed explanation. The storage is assigned to the servers by a SAN administrator. I think all I have to do is run the devfsadm command or to reboot with reconfigure option to identify the new disks. Please correct me if I am wrong. How do I identify if DRL or DCOs are configured on the servers?

Below are the list of things that I have done to gather some information:
1. Identify all the DGs in a server.
2. Identify all the disks and their sizes on each DG.
3. Volumes on each DG
4. Mounted File Systems on each server.

Please let me know if I am missing anything and if I need any further information.

Thanks
Kothur

 

[Annihilannic]

I'm a little bit rusty on Solaris SAN device configuration, and have done it very little on Solaris 9 and never on Solaris 10, so I'll allow others to advise on that. However it may involve manual updates to some kernel driver config files for your HBAs (in /kernel/drv and/or /platform/`uname -m`/kernel/drv) to allow them to "see" the new ports on the SAN, and possibly updates to the /kernel/drv/sd.conf to allocate more "slots" for the new devices. Hopefully this is a little less manual on later versions.

vxprint -Ath | grep ^dc will tell you whether any DCOs are configured, and vxprint -Ath | grep -w LOG will do the same for DRLs.

Incidentally, you may consider waiting for a while (a few days to a week) between steps 4 and 5 in my procedure just to make sure everything is running smoothly on the new storage before you drop the original mirrors.

Annihilannic.

 

[kothur]

Yes we are planning to wait for 2-3 three weeks before we break the mirrors.

Regarding configuring the sd.conf files. I have read in some of the other forums that if the leadville drivers are installed then you don't have to update the sd.conf or qlxxx.conf files. I see that SUNWsan and SUNWqlc packages are already installed in the servers and I think these are the SUN leadville drivers. Anybody can correct me if I am wrong.

Thanks for all your help.