On 2017-08-31 20:49, Austin S. Hemmelgarn wrote: > On 2017-08-31 13:27, Goffredo Baroncelli wrote: >> Hi All, >> >> >> I found a bug in mkfs.btrfs, when it is used the option '-r'. It >> seems that it is not visible the full disk. >> >> $ uname -a Linux venice.bhome 4.12.8 #268 SMP Thu Aug 17 09:03:26 >> CEST 2017 x86_64 GNU/Linux $ btrfs --version btrfs-progs v4.12 > As far as I understand it, this is intended behavior. Tools that > offer equivalent options (genext2fs for example) are designed to > generate pre-packaged system images that can then be resized to fit > the target device's space. As an example use case, I do full system > image updates on some of my systems (that is, I keep per-system > configuration to a minimum and replace the entire root filesystem > when I update the system) I use this option to generate a base-image, > which then gets automatically resized by my update scripts to fill > the partition during the update process.
Sorry, but I am a bit confused. If I run "mkfs.btrfs -r ...." on a partition... how I can detect the end of the filesystem in order to cut the unused space ? >From your explanation I should do # mkfs.btrfs -r <source> /dev/sdX then # dd if=/dev/sdX of=/tmp/image bs=1M count=NNNN What I have to put in NNNN ? genext2fs in effect works generating a file. Instead mkfs.btrfs seems to work only with disks (or file already created)... > > Overall, this could probably stand to be documented better though > (I'll look at writing a patch to update the documentation to clarify > this when I have some spare time over the weekend). This would be great. However I think that some code should be update in order to generate a file instead of rely on a block device. BR G.Baroncelli -- gpg @keyserver.linux.it: Goffredo Baroncelli <kreijackATinwind.it> Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
