Storage to SAN Migration

Hi, We are working with our vendor on migrating our Databases from Local Storage to SAN. Our Database is using the Raw Partion. Vendor has advised that they will create a similar character device link in the system from SAN ( we have around 250 character device links) and then copy data from the existing character devices to the new SAN devices. Once data is copied they will rename the SAN links to the original character device links. My question ..This is possible... ( copying data from character devices links, renaming character devices .. ) People who have done this type of migration can share their thoughts. Thanks in advance. Dhaya

> Hi, > > We are working with our vendor on migrating our Databases from Local > Storage to SAN. Our Database is using the Raw Partion. Vendor has > advised that they will create a similar character device link in the > system from SAN ( we have around 250 character device links) and then > copy data from the existing character devices to the new SAN devices. > Once data is copied they will rename the SAN links to the original > character device links. > > My question ..This is possible... ( copying data from character > devices links, renaming character devices .. ) > Firstly the engine has to be offline - and backed up of course. If the names of the devices are identical then the engine is oblivious to the move. Wise admins use symbolic links for the "device" names so that the engine is insulated from movements of chunks. Sometimes when a disk crashes, the replacement or it's partitions have a different name, so it's not unexpected to move chunks around. There are a few tricks you can use 1/ keeping the engine running, add mirror chunks on the new device for all your chunks. Bring the mirrors online - some time will elapse before they are synced. Once all the mirrors are online you can remove the old chunks. Practice this first, there's one or two points to take care of during the process. 2/ the restore operation can be told to rename the chunks as they are loaded. So you can take an archive, shut down the engine, restore it into the new location, and if it goes well you can use it running on the new chunks, otherwise go back to the old chunks and try again. Save a copy of the $ONCONFIG in case you need to revert to the old config.

Yes, as long as the server is offline or blocked (onmode -c block) during the copy it will work out fine. However, your chunks should not be pointing to the actual device links, you should be using links to those devices with paths in another location. If you are using IDS 11.xx you can also rename your chunk paths to links pointing to the new devices rather than rename the devices. Art Art S. Kagel Oninit (www.oninit.com) IIUG Board of Directors (art@iiug.org) Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on my employer, Oninit, the IIUG, nor any other organization with which I am associated either explicitly or implicitly. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves. On Tue, Oct 13, 2009 at 2:10 AM, sdhaya <dhaya.snidhi@gmail.com> wrote: > Hi, > > We are working with our vendor on migrating our Databases from Local > Storage to SAN. Our Database is using the Raw Partion. Vendor has > advised that they will create a similar character device link in the > system from SAN ( we have around 250 character device links) and then > copy data from the existing character devices to the new SAN devices. > Once data is copied they will rename the SAN links to the original > character device links. > > My question ..This is possible... ( copying data from character > devices links, renaming character devices .. ) > > People who have done this type of migration can share their thoughts. > > Thanks in advance. > > Dhaya > _______________________________________________ > Informix-list mailing list > Informix-list@iiug.org > http://www.iiug.org/mailman/listinfo/informix-list >