On Wed, Sep 04, 2019 at 12:03:10PM +0300, Andrei Borzenkov wrote: > On Wed, Sep 4, 2019 at 9:16 AM Swâmi Petaramesh <sw...@petaramesh.org> wrote: > > > > Hi list, > > > > Is there an advised way to completely “clone” a complete BTRFS > > filesystem, I mean to get an exact copy of a BTRFS filesystem including > > subvolumes (even readonly snapshots) and complete file attributes > > including extended attributes, ACLs and so, to another storage pool, > > possibly defined with a different RAID geometry or compression ? > > > > As long as you do not use top level subvolume directly (all data is > located in subolumes), send/receive should work. > > > The question boils down to getting an exact backup replica of a given > > BTRFS filesystem that could be restored to something logically > > absolutely identical. > > > > The usual backup tools have no clue about share extents, snapshots and > > the like, and using btrfs send/receive for individual subvols is a real > > pain in a BTRFS filesystem that may contain hundreds of snapshots of > > different BTRFS subvols plus deduplication etc. > > > > Shared extents could be challenging. You can provide this information > to "btrfs send", but for one, there is no direct visibility into which > subvolumes share extents with given subvolume, so no way to build > corresponding list for "btrfs send". I do not even know if this > information can be obtained without exhaustive search over all > extents. Second, btrfs send/receive only allows sharing of full > extents which means there is no guarantee of identical structure on > receiving side.
So right now the only answer is: use good old dd? Piotr Szymaniak. -- Jedyne napisy, które rozumie każdy Amerykanin, to "Wyprzedaż", "Za darmo" i "Seks". Kiedyś widziałem w Arizonie tablicę "Seks za darmo. Ograniczenie prędkości do 60 km/h". -- Nelson DeMille, "The Lion's Game"
