On 2019-11-30 08:12, Raymond, David 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?
it's more complicated, and thus, will have more bugs. My personal experience: I'd trust softdep more than any modern Linux filesystem, BUT its still more complicated, and thus will have more bugs than the default FFS. > On SSDs in particular, is it worth setting noatime to reduce the > number of disk writes? Nothing to do with SSDs, as your quest to minimize writes on SSDs is demonstrated stupid and pointless. SSDs fail much more often for reasons other than write fatigue, Optimizing for write fatigue is like protecting your ship against icebergs hitting the propeller. VERY VERY few applications use atime, and yet, it requires an update to the directory for EVERY SINGLE ACCESS. Ouch. So, it's a non-trivial performance gain if you turn it off. That's a great reason to turn it off. Not SSDs. HOWEVER...if you don't need performance and you can't point to a real benefit, as always, keep it on the default. Nick.
