Re: moving instance old drives to new

Kevin wrote: > > Hey Boys and Girls! > > We are about to attempt to move an instance from 1 set of drives to a new > set of drives on the same machine. I am looking for any and all suggestions > on the best way to accomplish this. > In addition to the drive change, there will be changes to the dbspace names > (some will remain the same) and sizes( bigger). I'm thinking I need the > dbspaces to remain intact while I insert/select into the new dbspaces. I've > sort of eliminated a backup/restore scenario since the dbspace names > couldn't be changed. The DB is about 100 GB which I don't think we would > have the space for a dbexport/dbimport. This is the production machine and > I'm going to try to accomplish this over a weekend. We are planning on > bringing the memory from 1.5 GB to 3 Gb. This is on Solaris 2.6 on a 4 CPU > Enterprise 3000 with IFMX 7.30. > > Q. Is this the way to go? Am I missing a far easier scenario? Assuming you are using symbolic links for your chunk names (you did do this didn't you?) all you need to do is shutdown the engine, use dd to copy each old chunk to a new device, recreate the symbolic links to point to the new devices, and bring the engine back online! Of course if you are using actual device names then this is FAR more difficult to accomplish as you have to deregister the original devices and replace them with links to the new devices and having symbolic links in the /dev structure is a sysadmin's nightmare. > Q. Can the INFORMIXSERVER and aliases be renamed back to the old names once > the original instance is dropped? Yes. Even the SERVERNUM. Just bring both instances down, edit the new ONCONFIG file to change the server name and aliases back and restart the new server. > Q. Could I do this with one instance and somehow rename the dbspaces later? > The devices are currently the c0t3d0s0 nomenclature, these will become Vol01 > vol02 etc etc with the Veritas Storage Mgr. The devices are symbolically > linked. Would this allow me to create another set of links and have dbspaces > with the same name? See my first comment, but, YES! > Q. What are the gotchas for creating a 2nd instance (temporarily) on the > same machine. Kernal parameters need to be changed? Etc. ETc. > I am planning on capping each instance to only use 1/2 the memory with the > SHMTOTAL parameter. Anything else??? Some kernel parameters, usually SHMMAX and a few others, may be too low if you only pushed them as far as the release notes suggested, for a second instance. Just ran into that one myself yesterday. Art S. Kagel