I'm trying to tune my filesystem for some operations I have to do involving huge numbers of files. Then I got confused about what FS I'm even using.
tune2fs -l /dev/vda1 contains:
Filesystem magic number: 0xEF53
So that means it's either ext2, ext3 or ext4 because they share the same magic number.
blkid /dev/vda1 says:
/dev/vda1: UUID="c38b3343-603a-49d3-85e0-88af1c8617c5" TYPE="ext3" PARTUUID="1bf082a8-01"
UUID=c38b3343-603a-49d3-85e0-88af1c8617c5 / ext3 (...)
mount (and /proc/mounts) says:
/dev/vda1 on / type ext3 (rw,relatime,errors=remount-ro,data=ordered)
Definitely seems like I'm using ext3.
But then, out of the middle of nowhere:
liam@lorenz /sys/fs % ls cgroup ext4 pstore liam@lorenz /sys/fs % ls ext4 features vda1 liam@lorenz /sys/fs % cd /proc/fs liam@lorenz /proc/fs % ls ext4 jbd2 nfsd liam@lorenz /proc/fs % ls ext4 ext4
What is going on? It's been ext3 since this VM was built and was never converted or mounted as ext4.
Linux lorenz 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt9-3~deb8u1 (2015-04-24) x86_64 GNU/Linux