Re:NetBSD 11 desktop on a Raspberry Pi 4
by yjftsjthsd-h on Tuesday November 10, 2026 @05:32PM
(#50447251)
Okay, so cat && sync
Re:NetBSD 11 desktop on a Raspberry Pi 4
by skrellm on Tuesday November 10, 2026 @06:21PM
(#50447722)
May not work, OS dependent. According to POSIX "sync" flushes the file system level buffer cache of opened files, and not necessarily the block device cache inside the kernel. (Eg. "sync" flushes devfs under /dev, so updates the /dev/sda directory entry, but maybe not the block cache of the (8,0) device.)
There's a good reason why the dd command exists, believe me.
FYI: https://linux.die.net/man/2/sync syscall is not the same as https://linux.die.net/man/2/fsync syscall.
ddrescue worked for me better than dd.
Re:NetBSD 11 desktop on a Raspberry Pi 4
by somat on Wednesday November 11, 2026 @03:20AM
(#50450924)
For what it's worth, probably not much, openbsd still has raw devices /dev/rsd1a vs /dev/sd1a(the block device) while it looks like linux made them all block devices (unless opened a special way O_DIRECT) and freebsd(as best I can tell) made all devices raw. https://docs-archive.freebsd.org/doc/11.2-RELEASE/usr/local/...
So, on openbsd, make sure you use the raw device when writing images with dd, and in my experience you want to use dd because the block size on cat is too small. dd bs=64k if=image.file of=/dev/rsd2c (c on obsd is entire disk)
Definitely not. In fact, even dd is insufficient unless you use os specific flags to flush the disk cache, otherwise your stick might be corrupted. Read about the fdatasync syscall.