On Mon, Aug 03, 2009 at 09:32:32AM +0000, Stuart Henderson wrote: > On 2009-08-03, Jan Stary <[email protected]> wrote: > > On Jul 30 22:06:41, Stuart Henderson wrote: > >> On 2009-07-30, Jan Stary <[email protected]> wrote: > >> > is 128M, that's why I use xserv45.tgz and not base45.tgz; > >> > and it should have been tar xzpf I guess - does it make > >> > a difference? And it shloud be done in single user - but > >> > the machine is almost idle, really.) > >> > >> xserv has a small number of large files, whereas base has a mixture, > >> but it has a lot of small files in it. xzpf won't matter for this test, > >> but if my theory is right, you will need to write lots of small files > >> to see a difference. > > > > I just repeated the same test ten times with xfont45.tgz (is that > > a lot of small files?) - with 'async' it consistently takes between > > 4:00 and 4:10. With 'softdep', it consistently takes between 4:40 > > and 4:50. > > interesting, I don't know why that is, then. > > > Which leaves the original question unanswered: why is the untaring > > during an install so slow when it's async, which I just found to > > perform better than softdep on a running system? > > > >> > For some reason (no reason), I have always thought that nothing can > >> > be faster than async. What is the rationale for mounting the target > >> > filesystems async mounts during an install, anyway? > >> > >> It's a lot faster than mounting them sync. (ramdisks don't have softdep, > >> and also softdep on OpenBSD doesn't free up space from pending deletes > >> quickly enough to be a good choice for untarring new OS file sets). > > > > Again I am confused: how much pending deletes are there during an install > > when untaring the OS sets? > > when you update an already-installed system, loads. >
And keep in mind that the ramdisk kernels don't come with softdep. So on updates the filesystem is mounted sync whereas on installs it is async. -- :wq Claudio
