On 10/23/17 22:07, Daniel Boyd wrote: > On Oct 23, 2017, at 8:57 PM, Daniel Boyd <danieljb...@icloud.com> > wrote:
>>> But ... for unpacking ports, make sure that file system is >>> mounted (at the OpenBSD level) with softdeps. Yes, it's really a >>> huge difference for lots of tiny files, which is exactly what the >>> ports tree is. This will matter more than hypervisor knobs, I >>> suspect. >>> >>> Nick. >>> >> > > Also, out of curiosity, why is softdep not enabled by default? > Assume there must be some downside to having it on? > It was discussed a few times, as I recall. Short version is, it's more complex code. You don't add code and make things more reliable and more secure, and softdeps are definitely more code. It does use more RAM, and it can cause funny things to happen in failure situations. Myself, I've last had a problem with the softdep code probably 12 years ago...and I submitted a bug report and got a fix a day or so later. I've turned it off on a few machines when I thought I might be having an issue, and found out that no, it was always something else. Me? I'd make it the default. But it does do things "differently" than people sometimes expect. It reorders writes. It holds a lot of data in RAM before it gets to disk. That causes "issues" when you trip over power cords. If you are doing lots of tiny file writes, performance on other applications may suffer (that's been improved a lot over the years, but still noticable, iirc). Funny things happen that people don't expect if you run out of disk space or crash or unplug the computer. So ... if the absolutely safest, most reliable FS is your desire, don't use softdeps. If you want something that probably still beats the Linux file system of the month, and is a lot faster than the standard FS options, use softdeps. Nick. Nick.
