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--- software:linux:btrfs [2016/11/11 00:32] – superwizard
+++ software:linux:btrfs [2016/11/17 03:26] (current) – superwizard
@@ Line 1: / Line 1: @@
+====== Scripts for btrfs maintenance tasks like periodic scrub ======
+From: https://github.com/kdave/btrfsmaintenance
+<code>
+Great Documentation
+Scripts for btrfs maintenance tasks like periodic scrub, balance, trim or defrag on selected
+mountpoints or directories.
+</code>
 ====== btrfs check ======
 From: https://btrfs.wiki.kernel.org/index.php/Manpage/btrfs-check
-<>
+<code>
 btrfs check /dev/sb2
 btrfs check --repair \dev\sb2
-<>
+</code>
+====== btrfs scrub ======
+From: http://marc.merlins.org/perso/btrfs/post_2014-03-19_Btrfs-Tips_-Btrfs-Scrub-and-Btrfs-Filesystem-Repair.html
+From: https://btrfs.wiki.kernel.org/index.php/Manpage/btrfs-scrub
+<code>
+btrfs scrub start -Bd $mountpoint
+btrfs scrub is used to scrub a btrfs filesystem, which will read all data and metadata blocks from
+all devices and verify checksums. Automatically repair corrupted blocks if there’s a correct copy
+available.
+start [-BdqrRf] [-c <ioprio_class> -n <ioprio_classdata>] <path>|<device>
+Start a scrub on all devices of the filesystem identified by path or on a single device. If a scrub is already running, the new one fails.
+Without options, scrub is started as a background process.
+The default IO priority of scrub is the idle class. The priority can be configured similar to the ionice(1) syntax using -c and -n options.
+Options
+-B
+do not background and print scrub statistics when finished
+-d
+print separate statistics for each device of the filesystem (-B only) at the end
+-q
+be quiet, omit error messages and statistics
+-r
+run in read-only mode, do not attempt to correct anything, can be run on a read-only filesystem
+-R
+print raw statistics per-device instead of a summary
+-c <ioprio_class>
+set IO priority class (see ionice(1) manpage)
+-n <ioprio_classdata>
+set IO priority classdata (see ionice(1) manpage)
+-f
+force starting new scrub even if a scrub is already running, this can useful when scrub status
+file is damaged and reports a running scrub although it is not, but should not normally be necessary
+status [-d] <path>|<device>
+</code>
+====== resize partition ======
+From: http://unix.stackexchange.com/questions/239765/how-to-fix-btrfs-superblock-error-after-resize-shrink-btrfs-couldnt-get-super
+<code>
+Fix
+First, a live system was booted to reduce the risk of damage while the system is running on a
+filesystem that's bigger than the partition it's on.
+Mount the filesystem:
+mount /dev/sda2 /mnt/tmp
+First shrink the second device to 50 GB - 1 GB = 49 GB to avoid rounding errors:
+btrfs filesystem resize 2:49g /mnt/tmp
+Resize it to fill the 50 GB partition:
+btrfs filesystem resize 2:max /mnt/tmp
+Check btrfs filesystem show, both devices should have the right size:
+devid    1 size 50.00GiB used 43.03GiB path /dev/sda2
+devid    2 size 50.00GiB used 43.03GiB path /dev/sdb2
+Unmount, reboot, the error should be gone.
+</code>
 ====== BTRFS restoring a corrupt filesystem from another “tree location” ======