Besides, swap FILES are extremely slow as opposed to true swap PARTITIONS.
And multiple swap partitions will be reasonably fast only if placed on
different (physical) hard drives (like in a RAID system). Remember to give
each swap partition entry in your /etc/fstab the same pri=xx statement.
Best regards,
Cornelius
On Mon, 11 Oct 2004 11:26:30 +0100, Stephen Smith <[log in to unmask]>
wrote:
> Sure - that all makes sense, thanks. Though note - I was referring not to
> maximum swap size, but there's a separate point, which is that I think
> that on some OS's there is a limit to the max size that a single process
> can have, which I think may be 2GB on linux - I think there's ways to
> change that.
>
> Cheers.
>
>
>
> On Mon, 11 Oct 2004, Denis Brown wrote:
>
>> For what it's worth...
>>
>> Bear in mind that you can set up multiple swap partitions or swap files
>> (each 2GB in size) and use them. If I recall reading correctly, up to
>> eight partitions/files can be used to give the equivalent of 16GB under
>> a
>> 2.4 series kernel. The 2.6 kernel may have expanded that. I have
>> never
>> had to set up systems that support more than a single swap partition so
>> I
>> cannot speak from experience.
>>
>> Best regards,
>> Denis
>>
>>
>> On Mon, 11 Oct 2004, Stephen Smith wrote:
>>
>> > Hi. This is a very large dataset - you'll need quite a lot more swap
>> > probably - try 4GB (though you may have a problem with the 2GB process
>> > limit on linux if you need more than that - though I think you can
>> > change the kernel params to increase that?).
>> >
>> > Cheers.
>> >
>> >
>> > On Fri, 8 Oct 2004, Axel Thielscher wrote:
>> >
>> > > Hi - I try to analyze an EP image series created with AFNI using the
>> > > GLM-module of FSL. I used 3dAFNItoANALYZE provided by AFNI to
>> transform the
>> > > EP BRIK to an 4D-Analyze-File. The size of this file is either
>> around 630 MB
>> > > (voxel values stored as integer) or 1.3GB (voxel values stored as
>> floating
>> > > point) and it contains 1280 volumes of one session.
>> > >
>> > > The analysis with FEAT doesn't work with either of the two files.
>> More
>> > > specifically, the command
>> > > /usr/local/fsl/bin/film_gls -rn stats -noest filtered_func_data
>> design.mat
>> > > 11.12 3201
>> > > fails and is apparently unable to read to file.
>> > >
>> > > My computer: Red Hat Linux 9, Intel P-4, 1GB RAM, 2GB swap space
>> > >
>> > > Does this problem stem from insufficient swap space? The analysis
>> with AFNI
>> > > works fine, but I would be happy to use the more advanced features
>> such as
>> > > prewhitening etc. provided by FSL. How much memory do you recommend
>> for
>> > > input file sizes as quoted above? Can this failure be caused by a
>> different
>> > > problem?
>> > >
>> > > Thanks,
>> > > Axel
>> > >
>> >
>> > Stephen M. Smith DPhil
>> > Associate Director, FMRIB and Analysis Research Coordinator
>> >
>> > Oxford University Centre for Functional MRI of the Brain
>> > John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
>> > +44 (0) 1865 222726 (fax 222717)
>> >
>> > [log in to unmask] http://www.fmrib.ox.ac.uk/~steve
>> >
>>
>
> --
> Stephen M. Smith DPhil
> Associate Director, FMRIB and Analysis Research Coordinator
>
> Oxford University Centre for Functional MRI of the Brain
> John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
> +44 (0) 1865 222726 (fax 222717)
>
> [log in to unmask] http://www.fmrib.ox.ac.uk/~steve
>
--
Cornelius Werner, AiP
Institut fuer Medizin (IME)
AG Kognitive Neurologie
Forschungszentrum Juelich
52425 Juelich
Germany
Tel. +49-(0)2461-61-8609
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