Messages in this thread | | | Date | Wed, 9 Jun 1999 08:30:17 +0200 (CET) | From | Juan Antonio Martinez <> | Subject | Re: cachefs module for linux? |
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On Tue, 8 Jun 1999, Jeff Garzik wrote:
> Date: Tue, 8 Jun 1999 11:39:27 -0400 (EDT) > From: Jeff Garzik <jgarzik@pobox.com> > To: Christoph Lameter <christoph@lameter.com> > Cc: Juan Antonio Martinez <jantonio@dit.upm.es>, linux-kernel@vger.rutgers.edu > Subject: Re: cachefs module for linux? > On Tue, 8 Jun 1999, Christoph Lameter wrote: > > On Tue, 8 Jun 1999, Jeff Garzik wrote: > > > On Tue, 8 Jun 1999, Juan Antonio Martinez wrote: > > > > 1- Are there any fs module to implement a local disk cache over > > > > NFS readonly mounted filesystems? Something about Solaris's cachefs > > > cachefs gets mentioned now and again, and is very useful. We used it on > > > the cnn.com Web farm, where we had one big machine (NFS server) and > > > several Web servers all mounting the big server's drives with > > > nfs+cachefs. cachefs really improved throughput, but cnn.com uses > > > almost exclusively static files. > > squid does the same in a far more elegant way as we implemented for > > the Sony Motion Pictures site. NFS is the wrong solution and the wrong > > protocol for web caching.
So you suggest something like webNFS?. Perhaps is an action to study...
> True, but Squid didn't exist, or wasn't well known in 1996. > > I thought NFS already did some caching? > Not enough for the CNN Web site, which is probably at least half a > terabyte of stories by now. The large selection set of > frequently-viewed pages demands something more than simple buffer > cache. > cachefs comes in really handy, too, setting up "diskless" machines with > nothing but NFS cache and swap space. > This is my problem: I manage a students lab with 100+ NFS clients and 4 binary apps NFS servers. Every client has a small ( about 400MB ) hard disk to store a tftp retrieved mini root filesystem ( about 20 MB ) and a swap. /usr /home, and so are nfs mounted. Specifically /usr is readonly and need to manage large apps ( Xserver, java compiler, netscape, and so) in a more efficient way than NFS cache offers ( some clients has only 16Mb RAM )
You'll say: use coda . OK but our feeling is that coda is still too unstable to manage about 1500+ users and 100+ clients in an "hostil" environment such a students lab. Item more: we need quotas, file locking and so that are still not supported in coda ( needed for the /home directory )
So a hard disk cache for readonly netmounted filesystems seems the ideal solution for us. Of course: using knfsd, 100Mb network, load balanced servers, etc... neither servers nor network are now the problem. Just need to improve eficiency in clients
Juan Antonio \|||/ / _ _ \ \ o o / =========================o00o===U===o00o====================================== Juan Antonio Martínez Universidad Politécnica de Madrid email: jantonio@dit.upm.es E.T.S.I Telecomunicación http://www.dit.upm.es/~jantonio Ciudad Universitaria s/n Tel: 34-1-5495700 ext 328 Centro de Cálculo Fax: 34-1-3367333 Madrid, Spain ============================================================================== Allways look for the right side of life - Monty Phyton en "La vida de Brian"
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