Revision as of 10:05, 20 January 2022

SnapRAID / MergerFS

Setup

https://zackreed.me/setting-up-snapraid-on-ubuntu/

Note that if (like me) you use a dedicated snapraid content directory then you'll need to create that by hand for each disk with:

 mkdir /mnt/data/disk1/.snapraid

Partitioning a new data disk

Note: "-m 2" here reserves 2% of the filesystem for root-owned files (eg. .../.snapraid/content)

 sudo parted -a optimal -s /dev/sdX -- mklabel gpt mkpart primary 0% 100%
 sudo mkfs.ext4 -m 2 -T largefile4 /dev/sdX1

Partitioning a new parity disk

Note: "-m 0" here reserves 0% of the filesystem, ensuring that the parity disks are slightly larger than the data disks

 sudo parted -a optimal -s /dev/sdX -- mklabel gpt mkpart primary 0% 100%
 sudo mkfs.ext4 -m 0 -T largefile4 /dev/sdX1

Adding a new data disk to mergerfs

From: https://zackreed.me/mergerfs-neat-tricks/ From within the root of the mergerfs filesystem (eg. /srv)

 xattr -w user.mergerfs.srcmounts '+>/mnt/data/disk4/srv' .mergerfs

Removing a data disk from mergerfs

From within the root of the mergerfs filesystem (eg. /srv)

 xattr -w user.mergerfs.srcmounts '-/mnt/data/disk4/srv' .mergerfs

Forcing a resync

 sudo snapraid sync

Identifying/Fixing a bad block

• https://www.smartmontools.org/wiki/BadBlockHowto
• Mdadm#Repairing_failing_disk_on_degraded_array