> Whenever I start my laptop up, /home takes ~17-19 seconds to mount You can always use x-systemd.automount in fstab, which delays the mount to the first access (ie. non-root login), or mask home.mount to be non-blocking (oneshot), so it runs parallel with the login manager and password input. Slow mount times are usually caused by large log trees and fragmented metadata. Try the autodefrag mount option and btrfs fi defrag -clzo -t 2M -r /home (defragment files over 2M in size, recompress with lzo, recursively), btrfs balance start /home (and wait for btrfs-endio-wri to calm down or check with balance status, this takes some time) If those don't help enough, try checking (but not repairing) the device with btrfsck, and, if it's clean, clear the logs with btrfs-zero-image after backing up the metadata with btrfs-image (consult the btrfs mailing list or IRC first, I am not an expert in this). > Running df -h on my system, I get: > /dev/sda5 422G 364G 53G 88% /home Please use btrfs filesystem df (fi df for short), as it will show you both the data and metadata allocation with better reflection on actual free data space. Point is, the allocation on B* trees can only be measured by a full tree traversal (as your du try shows the true data usage, but misses fragmentation), but btrfs usage is even more complicated. Authors suggest that a device never be filled over 75% to avoid metadata fragmentation, but by having larger files this can truly be about 95%. Sorry for the long text, but I belive this helps in better understanding. --Oliver Temlin
