CNFS buffers bigger than 2 GB under Linux ?

[Antoine Delvaux]

Le 2002.03.17 08:58, Russ Allbery a =E9crit :
>=20
> Antoine Delvaux <antoine.delvaux at belnet.be> writes:
>=20
> > I don't know what's exactly the status of running innd with CNFS buffer
> > bigger than 2 GB under Linux.  Can someone share its experience ?
>=20
> > I'm trying to setup a newsfeeder with two CNFS buffers of 54 GB.  The
> > box is running Linux 2.4.17 with enable large memory (64 GB) and I've
> > compiled innd with the --with-largefiles option (tweaking a bit with the
> > makefile and taking the compile options of hpux : -D_LARGEFILE_SOURCE
> > -D_FILE_OFFSET_BITS=3D64).
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> I've never used CNFS on Linux, but I believe Linux shares with Solaris the
> limitation that even with the latest kernels you can't mmap raw devices
> larger than 2GB.  Are you using raw devices by any chance instead of
> files?

Yes, I'm using raw devices.

I wanted to use a single raw devices as under it lies a RAID stripping=20
setup which already gives me the speed that I want.  I don't need much=20
flexibility neither as this server will be a feed only with nearly no=20
backlog and so only one article spool.

The problem with doing many 2GB devices is that the maximum SCSI partitions=
=20
a disk can have under Linux is 16 (or does anybody knows how to do more=20
?).  So with 108 I must do at least 4 differents RAID logical drives to be=
=20
under this limit.  This means I have to change the RAID configuration, I'm=
=20
not even sure I could do 4 logical drives, and it will not be an optimal=20
RAID setup I think.

I'll investigate this way though.

Anyway, thank you very much for your advices.

Antoine.