Inom TurdikulovBtrfs (better F S)
Btrfs includes native optimizations for SSD media. To enable these features, mount the Btrfs filesystem with the -o SSD mount option. These optimizations include enhanced SSD write performance by avoiding optimization such as seek optimizations which do not apply to solid-state media.
Asynchronous discard support is available with mount option discard=async, and
is enabled by default as of linux 6.2.
Here list of “safe” commands for btrfs:
mkfs.btrfs # create a btrfs filesystem
btrfs scrub # pass over all filesystem data and metadata and verifying the
# checksums, not same as fsck
btrfs balance # spread block groups across all devices so they match constraints
# defined by the respective profiles, it's NOT a defragmentation
btrfs device stats # show statistics about devices, 0 means no errors
btrfs filesystem df # show disk space usage information for a btrfs filesystem
btrfs filesystem du # show disk usage by files and directories for a btrfs
# filesystemPeriods for maintenance:
balance - weekly, example: btrfs balance -dusage=50 -dlimit=2
scrub - monthly, with full system backup
check discard=async is enabled by default as of linux 6.2. TODO: check actual
mount options.
btrfs check is not safe, it’s experimental and can corrupt data (2021).
Resize filesystem (root volume) to maximum size
# first check lsblk -f
parted /dev/sdb resizepart 2 100% # 2 here is partition numper
btrfs filesystem resize max /
btrfs fi show / # validate sizeWhat to do on a failed disk (btrfs) / TODO: NEED review and test…
https://superuser.com/questions/1087787/linux-btrfs-convert-to-single-with-failed-drive#:\~:text=Begin%20a%20rebalancing%20operation%20with,and%20size%20of%20your%20array. Do this in arch live-iso.
Convert Btrfs raid1 to single Btrfs
# Disable auto-mounting btrfs array in /etc/fstab, reboot
DISK_DEVICE=/dev/sd[x] # change to your disk name
MOUNT_POINT=/mountpoint # don't use spaces here
# Make disk inaccessible to the kernel
# echo 1 | sudo tee /sys/block/sd[x]/device/delete
# Mount your array, with -o degraded mode.
mount -o degraded "$DISK_DEVICE"2 "$MOUNTPOINT"2 # 2 is disk & mountpoint postfix /dev/sdb2 /mnt/sdb2
mount -o degraded "$DISK_DEVICE"3 "$MOUNTPOINT"3 # 3 is disk & mountpoint postfix /dev/sdb3 /mnt/sdb3
# if you have mount issues, try this
btrfs rescue zero-log /dev/<devicename>
# Begin a rebalancing operation
btrfs balance start -f -mconvert=single -dconvert=single "$MOUNTPOINT"2
btrfs balance start -f -mconvert=single -dconvert=single "$MOUNTPOINT"3
# Remove the 'missing' faulty device.
btrfs device remove missing "$MOUNTPOINT"2
btrfs device remove missing "$MOUNTPOINT"3
# Restore metadata redundancy
btrfs balance start -mconvert=dup "$MOUNTPOINT"2
btrfs balance start -mconvert=dup "$MOUNTPOINT"3
# Now check that it has worked
btrfs fi show
btrfs fi usagehttps://btrfs.wiki.kernel.org/index.php/Using_Btrfs_with_Multiple_Devices
We then shut down the system, plugged the replacement disk in (actually the disk we had earlier ruined by double degraded booting, after wiping the BTRFS partition), booted and then did the usual dance to turn the now-single BTRFS into a RAID1 again.
Restore gpt partiton from backup to new drive first (partitiontable),
and recommended restore EFI partition too. Instructions above.
# add multiple devices
btrfs device add /dev/sd[x] /boot
btrfs device add /dev/sd[x] /
# convert to raid1
btrfs balance start -dconvert=raid1 -mconvert=raid1 /boot
btrfs balance start -dconvert=raid1 -mconvert=raid1 /
# Now check that it has worked
btrfs fi show
btrfs filesystem df /As a result, we had a RAID1 again. If you wonder why we did not use Btrfs replace: We would have to connect the new disk before the second reboot, which is not always practical. With the method above, once we have rebalanced the file system to a single one, we can reboot as often as we like to get the new drive online.
Alternative https://btrfs.wiki.kernel.org/index.php/Using_Btrfs_with_Multiple_Devices#Using_btrfs_replace