Section 8: administration and privileged commands
btrfs-qgroup – control the quota group of a btrfs filesystem Synopsis btrfs qgroup <subcommand> <args> Description btrfs qgroup is used to control quota group (qgroup) of a btrfs filesystem. Note To use qgroup you need to enable quota first using btrfs quota enable command. Warning Qgroup is not stable yet and will impact performance in…
btrfs-property – get/set/list properties for given filesystem object Synopsis btrfs property <subcommand> <args> Description btrfs property is used to get/set/list property for given filesystem object. The object can be an inode (file or directory), subvolume or the whole filesystem. See the description of get subcommand for more information about both btrfs object and property. btrfs…
btrfs-map-logical – map btrfs logical extent to physical extent Synopsis btrfs-map-logical <options> <device> Description btrfs-map-logical can be used to find out what the physical offsets are on the mirrors, the result is dumped to stdout by default. Mainly used for debug purpose. Options -l|–logical <logical_num> Logical extent to map. -c|–copy <copy> Copy of the extent…
btrfs-inspect-internal – query various internal information Synopsis btrfs inspect-internal <subcommand> <args> Description This command group provides an interface to query internal information. The functionality ranges from a simple UI to an ioctl or a more complex query that assembles the result from several internal structures. The latter usually requires calls to privileged ioctls. Subcommand dump-super…
btrfs-image – create/restore an image of the filesystem Synopsis btrfs-image [options] <source> <target> Description btrfs-image is used to create an image of a btrfs filesystem. All data will be zeroed, but metadata and the like is preserved. Mainly used for debugging purposes. In the dump mode, source is the btrfs device/file and target is the…
btrfs-find-root – filter to find btrfs root Synopsis btrfs-find-root [options] <device> Description btrfs-find-root is used to find the satisfied root, you can filter by root tree’s objectid, generation, level. Options -a Search through all metadata extents, even the root has been already found. -g <generation> Filter root tree by it’s original transaction id, tree root’s…
btrfs-filesystem – command group that primarily does work on the whole filesystems Synopsis btrfs filesystem <subcommand> <args> Description btrfs filesystem is used to perform several whole filesystem level tasks, including all the regular filesystem operations like resizing, space stats, label setting/getting, and defragmentation. There are other whole filesystem tasks like scrub or balance that are…
btrfs-device – manage devices of btrfs filesystems Synopsis btrfs device <subcommand> <args> Description The btrfs device command group is used to manage devices of the btrfs filesystems. Device Management Btrfs filesystem can be created on top of single or multiple block devices. Data and metadata are organized in allocation profiles with various redundancy policies. There’s…
btrfs-inspect-internal – query various internal information Synopsis btrfs inspect-internal <subcommand> <args> Description This command group provides an interface to query internal information. The functionality ranges from a simple UI to an ioctl or a more complex query that assembles the result from several internal structures. The latter usually requires calls to privileged ioctls. Subcommand dump-super…
btrfs-convert – convert from ext2/3/4 or reiserfs filesystem to btrfs in-place Synopsis btrfs-convert [options] <device> Description btrfs-convert is used to convert existing source filesystem image to a btrfs filesystem in-place. The original filesystem image is accessible in subvolume named like ext2_saved as file image. Supported filesystems: • ext2, ext3, ext4 — original feature, always built…
btrfs-check – check or repair a btrfs filesystem Synopsis btrfs check [options] <device> Description The filesystem checker is used to verify structural integrity of a filesystem and attempt to repair it if requested. It is recommended to unmount the filesystem prior to running the check, but it is possible to start checking a mounted filesystem…
btrfs-balance – balance block groups on a btrfs filesystem Synopsis btrfs balance <subcommand> <args> Description The primary purpose of the balance feature is to spread block groups across all devices so they match constraints defined by the respective profiles. See mkfs.btrfs(8) section PROFILES for more details. The scope of the balancing process can be further…
btreplay – recreate IO loads recorded by blktrace Synopsis btreplay [ options ] <dev…> Description The btrecord and btreplay tools provide the ability to record and replay IOs captured by the blktrace utility. Attempts are made to maintain ordering, CPU mappings and time-separation of IOs. The blktrace utility provides the ability to collect detailed traces…
btrecord – recreate IO loads recorded by blktrace Synopsis Usage: btrecord [ options ] <dev…> Description The btrecord and btreplay tools provide the ability to record and replay IOs captured by the blktrace utility. Attempts are made to maintain ordering, CPU mappings and time-separation of IOs. The blktrace utility provides the ability to collect detailed…
btraceback – wrapper script around gdb and bsmtp Synopsis btraceback /path/to/binary pid Description btraceback is a wrapper shell script around the gdb debugger (or dbx on Solaris systems) and bsmtp, provided for debugging purposes. Usage btraceback is called by the exception handlers of the Bacula daemons during a crash. It can also be called interactively…
btrace – perform live tracing for block devices Synopsis btrace [-s] [-t] [-w N] [-n N] [-b N] [-r <dbg mnt>] [-a <trace>…] <dev>… Description The btrace script provides a quick and easy way to do live tracing of block devices. It calls blktrace on the specified devices and pipes the output through blkparse for…
btkbdd – Bluetooth Keyboard Daemon Synopsis btkbdd [-s addr] [-t addr] [-c file] [-d] device Description This tool starts a Bluetooth HID Keyboard service, serving keystrokes obtained via Linux Input subsystem’s event device (evdev). In practical terms, it turns your Linux box with a physical keyboard into a Bluetooth keyboard, which can be used by…
BTCFLASH – firmware flash utility for BTC DRW1008 DVD+/-RW recorder. Synopsis btcflash DEVICE FILE Description BTCFLASH may also work with other BTC DVD recorders, such as the DRW1004 and DRW1108, but they have not been tested. USE AT YOUR OWN RISK! Firmware files may be obtained by running BTC’s Windows flash utility, then searching in…
btape – Bacula’s Tape interface test program Synopsis btape [options] device-name Description This manual page documents briefly the btape command. Options A summary of options is included below. -? Show summary of options and commands. -b bootstrap Specify a bootstrap file. -c config Specify configuration file. -d nn Set debug level to nn. -p Proceed inspite of I/O…
bscan – Bacula’s ‘Scan tape’ Synopsis bscan [options] bacula-archive Description The purpose of bscan is to read (scan) a Bacula Volume and to recreate or update the database contents with the information found on the Volume. This is done in a non-destructive way. This permits restoring database entries that have been lost by pruning, purging, deleting,…