Rupert Gallagher [r...@protonmail.com] wrote: > No, I am not using USB. rsync between disks should be very fast. you are going from the sata to the nvme ? NetBSD or FreeBSD or somebody made some speed improvements to nvme that we should review. i can't remember right now. anyways, 10GB/hour sounds extremely slow for an nvme SSD, way way way too slow for anything I have experienced in recent memory.
it might be interesting to try using cp between filesystems, or tar such as: cp -r /usr/bin /mnt/usr/bin or: tar cf - -C /usr/bin . | tar xpf - -C /mnt/usr/bin also what speeds are you getting on the destination filesystem? dd count=1 bs=1G if=/dev/zero of=/mnt/test conv=fsync might give you some rough idea of what 1G write costs. here's 1G write on my Samsung 845DC Pro which is one of my all-time favorite SATA SSDs for reliability # dd count=1 bs=1G if=/dev/zero of=test conv=fsync 1+0 records in 1+0 records out 1073741824 bytes transferred in 2.906 secs (369450372 bytes/sec) here's the same for a Crucial M500 # dd count=1 bs=1G if=/dev/zero of=test conv=fsync 1+0 records in 1+0 records out 1073741824 bytes transferred in 4.356 secs (246484472 bytes/sec) it's not clear to me how much the buffer cache affects this but i'm hoping here that conv=fsync helps. in a wierd twist, tests like this with conv=fsync run consistently faster than without, so my understanding isn't that great.
