[fedora-arm] builder io isue

[Dennis Gilmore]

El Sun, 25 Dec 2011 22:43:15 -0800
Brendan Conoboy <blc at redhat.com> escribió:
> On 12/25/2011 09:06 PM, Gordan Bobic wrote:
> > Why not just mount direct via NFS? It'd be a lot quicker, not to
> > mention easier to tune. It'd work for building all but a handful of
> > packages (e.g. zsh), but you could handle that by having a single
> > builder that uses a normal fs that has a policy pointing the
> > packages that fail self-tests on NFS at it.
> 
> I'm not acquainted with the rationale for the decision so perhaps 
> somebody else can comment.  Beyond the packages that demand a local 
> filesystem, perhaps there were issues with .nfsXXX files, or some 
> stability problem not seen when working with a single open file? Not
> sure.

glibc uses functionality not supported on nfsv3. nfsv4 may be a viable
option. mock doesnt work right on nfs. i think looking at iscsi or aoe
or nbd would help to take out some of the layering thats in play
currently. I really think we need to get more spindles in play. all the
other arches use raid0 over local scsi/sas drives that are 10k or 15k
rpm. and the storage is local.  the only local option we have is to use
USB storage. maybe a 16GB usb stick on each may help. they can be
gotten for ~USD$16 each we are still going to be limited to the usb bus.

i really dont think we want more than 4 builders per disk.

<snip>
> It really begs the question: What are builers blocking on right now? 
> I'd assumed chroot composition which is rather write heavy.
> 

there is alot of random io throughout the build process. installing the
packages into the chroot is io intensive. building is not as io heavy,
linking often is. finding the files, extracting debuginfo, buildroot
cleanup,  writing the rpms, are all io heavy. you can generally be
assued that there will be 2 buildroots being initialised at once. ofen
its more.

Dennis