On 07/09/12 23:28, Steven Chamberlain wrote: [...] > Now with softupdates, metadata changes might cancel out in-memory and > they get written out a whole block at a time, so write latency is hardly > relevant any more. Yup, that seems decidedly plausible. Turns out that the spinning disk on the amd64 box has a write cache, which is enabled, so that would have hidden the problem. (It also has NCQ. I don't know whether the FreeBSD driver uses NCQ or not.) TBH I'd rather have the drive's write cache disabled anyway --- a proper filesystem shouldn't need it... [...] > The drawbacks were explained on this page (last paragraph) : > > http://www.freebsd.org/doc/handbook/configtuning-disk.html#SOFT-UPDATES I did actually read that, with some puzzlement, and eventually dismissed it as an archaism, because I wouldn't expect any other behaviour with a modern file system! Anyway, thanks for the assistance; I am actually planning to put this machine into active service reasonably soon... -- ┌─── dg@cowlark.com ───── http://www.cowlark.com ───── │ │ life←{ ↑1 ⍵∨.^3 4=+/,¯1 0 1∘.⊖¯1 0 1∘.⌽⊂⍵ } │ --- Conway's Game Of Life, in one line of APL
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