On Thursday, January 10, 2019 1:55:59 AM CET Dale wrote: > Wols Lists wrote: > > On 07/01/19 10:46, Dale wrote: > >> From what I've read, that can be overcome. If you get say a SMART > >> message that a drive is failing, > > > > Yup, I have to agree that SMART isn't always reliable, but if you > > *monitor* it, it should give plenty of warning of the recording medium > > failing ... > > Yep. It may not detect a spindle motor that is about to fail. I'm sure > it can't detect that lightening is about to strike and the drive get hit > with a surge either. It can generally tell if the media is failing > tho. I've read it can detect some components that are starting to fail > to, not all but some. Still, even tho it can't detect everything, it is > better than no warning at all. Until something better comes along, ESP > maybe, it will have to do. ;-) > > >> just remove that drive or remove the > >> whole LVM setup and use something else until a working drive setup can > >> be made. Once ready, then move the data, if the drive still works, to > >> the new drive. That is basically what I did when I swapped a smaller > >> drive for a larger one. I moved the data from one drive to another. It > >> did it fairly quickly. Someone posted that it may even be faster to do > >> it with LVM's pvmove than it is with cp or rsync. I don't know how true > >> that is but from what I've read, it moves the data really efficiently. > > > > Point is, it works at a different level. Both cp and rsync are NOT > > guaranteed to copy your filesystem accurately - mine is full of hard > > links and that will give both those two a hard and nasty time. > > > > LVM copies the block device underneath the file system, so it is less > > efficient in that it will copy 3GB if you have a 3GB partition, but it > > is far simpler in that it neither knows nor cares what the file system > > is doing at the next level up. Give a file-system like mine to "cp -a" > > and it'll bring the system to its knees trying to keep track of where > > everything is. > > > > Cheers, > > Wol > > That was what I read but couldn't recall enough to tell how it does it. > That explains why it can be done while in use to. > > Just how do you do backups? If cp -a and rsync would not work > correctly, what do you use? I'm just curious now. ;-)
There are backup tools that do handle hardlinks correctly. "app-backup/dar" comes to mind. I know this as my software-share is filled with hardlinks and when I restore the backup, they are all still there. -- Joost
