[systemd-devel] [ANNOUNCE] systemd 210

Lennart Poettering lennart at poettering.net
Tue Feb 25 05:29:34 PST 2014

On Tue, 25.02.14 13:05, Colin Guthrie (gmane at colin.guthr.ie) wrote:

> 'Twas brillig, and Lennart Poettering at 24/02/14 22:08 did gyre and gimble:
> >         * systemd will now understand the usual M, K, G, T suffixes
> >           according to SI conventions (i.e. to the base 1000) when
> >           referring to throughput and hardware metrics. It will stay
> >           with IEC conventions (i.e. to the base 1024) for software
> >           metrics, according to what is customary according to
> >           Wikipedia. We explicitly document which base applies for
> >           each configuration option.
> It would seem to me that use of upper and lower case suffixes is fairly
> wide-spread (at least in my head) for choosing which base (1000 vs
> 1024). Of course I can't remember which is which, but perhaps using this
> approach would actually be better - and default values can just use
> whichever letter-case they deem appropriate for the use-case.

Hmm, I thought about something like that, but I thought we'd the ones
inventing it, so I opted not to use that. Do you have some links which
could show that this is a more commonly accepted rule?

Note that in SI "m" is milli, and "M" is mega. Would be fun to store a
couple of millibyte on disk!

> I guess what I mean to say is that a general rule is easier to grok than
> a per-directive rule, although I may have missed some important
> subtleties and back discussion here.

This new rule we adopted basically results in IEC everywhere with the
exception of a few things like networkd's BitsPerSecond= setting. But
there it should be really obvious that it is SI that is meant, after all
"100Mbit Ethernet" or "Gigabit Ethernet" refer to SI prefixes. That
means the SI vs. IEC should come pretty natural I think for all
technical people the way it is right now. Or to turn this around, which
administrator would expect that setting BitsPerSecond= to 954K is the
right way to go for Gigabit Ethernet?


Lennart Poettering, Red Hat

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