One assumes that if you are migrating a filesystem to RAID, you are installing a new disk (for e.g. RAID 1) (you need multiple disks - as in the acoronym RAID). So, if you install your new disk alongside your existing disk, create a RAID mirror with only one partition (from the new disk) create a filesystem on the new "RAID with only one disk" - then copy the contents of your existing filesystem to your new filesystem. Then you can remove reference to your old filesystem from fstab and maybe use fdisk to change the partition type associated with it. Add the old disk (partition) to your new raid with mdadm - allow the mirrors to resync and you have your RAID 1 mirror. So i don't think "taking an existing partition and turning it into a RAID volume is going to be a big project". FYI M$ now allow "snapshots" be taken from their raid 1 setup and used as backups. Its relatively easy to achieve the same thing using LINUX raid but best to use a three way mirror - its just a matter of ensuring the filesystem is ideally unmounted before detaching a mirror) - although even if you don't - fsck can usually sort out any mess. Contrast that with unmounting a filesystem and doing a level 0 backup via dump or bacula and having your system offline for an hour or two! OK if you want to do incremental backups - its faster, but you sitll need media for each of your incrementals. I have even found that it is possible to detach a mirror and force the detached mirror to mount as a non-raid (ext3/4 or whatever) filesystem. (good for getting at your "backups". (expect smoke and flame here!) Andy I find it amusing that a few people give comments like "Raid, and rsyncing, are not equivalent to each other. They solve different problems" without actually defining in detail what they mean and why - without waffle! On Monday 09 March 2015 20:23:23 Sam Varshavchik wrote: > Bob Goodwin writes: > > I had a mainboard fail in a box I use as a server, I moved the hard drive > > into old computer and carried on from there. Now I've replaced the board > > and intended to set it up using Raid to mirror two drives. However I have > > been wondering if it wouldn't work just as well to periodically rsync the > > drive in use with a second drive? > > > > That seems a more direct approach and I could easily check to make certain > > that the second drive was a usable copy, insurance against loss of data. > > > > Am I going wrong somewhere in my thinking? > > Raid, and rsyncing, are not equivalent to each other. They solve different > problems. > > For starters, in your case taking an existing partition and turning it into > a RAID volume is going to be a big project. You'll have to back up your > existing data somewhere, erase the existing partition, create a raid > partition, then restore your data from backups. I'm not aware of a way to > turn an existing non-RAID partition into a RAID one. > > rsync is easier to set up when you have existing data, and I do have a few > laptops where I have a daily job to rsync their data onto a different > server. > > On the other hand, RAID is generally faster, and runs in realtime. With > rsync, you do have some window of vulnerability where you will lose > everything since your last rsync run, when you have a failure, where RAID > provides up to the second redundancy. -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
