I/O Schedulers: What They Actually Do, and Which One I Landed On

Why this even matters Every block device on Linux has an I/O scheduler sitting between your applications and the actual disk, deciding the order requests get sent in. Get the wrong one for your workload and you’re leaving real performance on the table, or worse, adding latency you didn’t need to. Check what’s currently active and what else is available: cat /sys/block/sda/queue/scheduler The one in brackets is active. On modern kernels you’ll usually see some combination of none, mq-deadline, kyber, and bfq listed. ...

July 18, 2026 · 4 min

Hard-Won Lessons Setting Up Samba + SFTP on a NAS

The idea was simple All I wanted was for my T620 to mount the QNAP shares, retire the QNAP as the “brain,” and have the T620 do everything … Samba, SFTP, the lot … while the QNAP just sat there as dumb storage in the background. Simple networking. I have never been more wrong about something taking one evening. Boot failure #1: the NFS ordering cycle First attempt, I set up NFS mounts from the QNAP onto the T620, then re-exported those same paths back out via NFS so other machines could reach them through the T620. Seemed logical … one machine, one point of access. ...

July 18, 2026 · 6 min