On 2019-11-30, Raymond, David <david.raym...@nmt.edu> wrote: > I am switching to OpenBSD from Linux and I have questions about the > use of softdep and noatime in mounting disks. I have a variety of > systems with a mix of SSDs and rotating disks. > > Softdep seems to have some advantages in speeding file access, but it > is not the default. Are there any downsides in using softdep?
Yes, that's why it's not on by default. Uses more memory, delays freeing space when removing files, tends to cause a kernel panic if the drive goes unresponsive (which the drive might have otherwise recovered from after a delay). It's not that much of an improvement with SSDs anyway, it's most useful with drives that are slow at random writes (higher seek times). > On SSDs in particular, is it worth setting noatime to reduce the > number of disk writes? In general, not really unless your drives are slow, or you often do reads across a large set of files and don't have anything that cares about access times on those files.