On Thu, 07 May 2026 10:33:06 +0200 Hans <[email protected]> wrote:
> Hi folks, > > just a question: Is there a tool in debian, which can create > partition images of mounted harddrives? > > I searched, but those I found, are all requesting to create from > unmounted devices. Looks like dd is promising, bur partclone, > clonezilla, parted and so on are all want an unmounted system. > > Please note, my aim is not getting the simple data (thus I could > easily use rsync), but want a full backup with partitions creating > from a running system (like clonezilla does). This system may not be > shut down! > > The question is: Does such a tool technically exist at all and is > that, what I want, technicalyl possible a all? > > I saw a similar tool for Windows years ago (I bleive it was > "AMANDA"),which could do this within a running Windows. But Windows > is not linux, so maybe this could npot be compared. > > (Please excuse, if my question sounds dumb). > > Thanks for your thoughtfulness and a short advice. > The problem is of course that while you are working your way through making a copy, some of the information both ahead of the copying and behind it may change. It is possible that these things have changed in an incompatible way, since those ahead of the copying process will get copied after the change, while the changes to earlier parts of the copy will not. The only way I know for sure of getting an accurate online copy is the LVM snapshot: https://linuxvox.com/blog/linux-lvm-snapshot/ This does of course require that you are already using LVM. Your existing system can be converted to LVM, but not online, there will be some downtime, and you also need to leave a chunk of space unused for the shadow copying to occur into. It would be a good time to buy a new drive if space is tight, and it is always a good idea to use LVM during installation of systems you would expect to backup e.g. servers. I don't use LVM on my sid workstation, as I store all non-trivial data on a separate server (which does use LVM), and if a sid installation breaks really badly, it will probably be better to do a clean installation. Windows has used shadow copying for at least twenty years, switchable per partition, making it relatively easy to make online backups. LVM has been around that long, but is not well publicised or routinely installed. -- Joe
