I've been sent off by a supervisor to find information on LVM and determine if a particular form of machine update is possible. I know nothing about LVM's and I'm not the most technically adept of people. If I do a good job researching this process and get all the cogent information, then, I may be allowed to perform the update under supervision. If I come back and all I can say is "It can/can't be done", then, I'll get a pat on the head but the general consensus will be disappointment in my efforts. I've read through the HOWTO and some other web references. We want to update our mail server (which uses LVM 1.0.8) on an old/slow disk-subsystem and mirror it (via software) to a newer/faster sub-system. The mirroring process would allow for a concurrent copy. We would then want to break the connection to the original disks and use the mirror as the new LVM system. My reading on LVM and raid arrays is a little unclear (to me -- which I suspect is a technical lack on my part). In the HOWTO, there's a section specifically on migrating data: http://www.tldp.org/HOWTO/LVM-HOWTO/removeadisk.html However, that looks like it mostly deals with a single hard drive being copied to another single hard drive. We have a raid array, which looks like it's covered more under this: http://www.tldp.org/HOWTO/LVM-HOWTO/recipemovevgtonewsys.html However in THAT case it seems like this is a workaround to copy without using a mirroring-type copy, but, simply taking one server down, starting the copy while the server is offline, and then putting the new server back online when the copy is over. This server needs to be up while the mirror is copying data over. Then, things seem to be complicated (at least to me) by this warning (from the HOWTO): It is not currently possible to add a disk to a striped logical volume in LVM 1. Use LVM 2 with the lvm 2 format metadata if you wish to be able to do so able to do so. I _think_ the above warning means that if I use RAID 2 or higher to copy from one subsystem to another, it won't work, but, RAID 1 (mirroring/duplexing) will work? So, with all that information... 1) With what I've provided, is it 'possible' to set up a software-based mirror between these two RAID disks sub-systems, bring them both up to being concurrent while the mail server is still live, and then break the mirror to go back down to having the new RAID array online? 2) If this is possible, is there a guide somewhere that explains this in at least some detail? I have directions on how to set up RAID 1 mirrors, but, I'm not sure what to do with LVM as part of the process. I have tried to do the majority of my research before asking these questions...I'm just having some trouble putting the peices I have "together". Gwen __________________________________ Do you Yahoo!? The all-new My Yahoo! - What will yours do? http://my.yahoo.com _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
