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RE: [reiserfs-list] Re: benchmarks

To: "'Xuan Baldauf'" <xuan--reiserfs@xxxxxxxxxxx>, Nikita Danilov <NikitaDanilov@xxxxxxxxx>
Subject: RE: [reiserfs-list] Re: benchmarks
From: "Gonyou, Austin" <austin@xxxxxxxxxxxxxxx>
Date: Mon, 16 Jul 2001 14:57:21 -0500
Cc: linux-xfs@xxxxxxxxxxx, reiserfs-list@xxxxxxxxxxx
Sender: owner-linux-xfs@xxxxxxxxxxx
Wouldn't GFS be a good idea then?

-- 
Austin Gonyou
Systems Architect, CCNA
Coremetrics, Inc.
Phone: 512-796-9023
email: austin@xxxxxxxxxxxxxxx 

> -----Original Message-----
> From: Xuan Baldauf [mailto:xuan--reiserfs@xxxxxxxxxxx]
> Sent: Monday, July 16, 2001 2:34 PM
> To: Nikita Danilov
> Cc: Hans Reiser; Russell Coker; Chris Wedgwood; 
> rsharpe@xxxxxxxxxx; Xuan
> Baldauf; Seth Mos; Federico Sevilla III; linux-xfs@xxxxxxxxxxx;
> reiserfs-list@xxxxxxxxxxx
> Subject: Re: [reiserfs-list] Re: benchmarks
> 
> 
> 
> 
> Nikita Danilov wrote:
> 
> > Hans Reiser writes:
> >  > Russell Coker wrote:
> >  > >
> >  > > On Mon, 16 Jul 2001 11:00, Chris Wedgwood wrote:
> >  > > > On Sun, Jul 15, 2001 at 02:01:09PM +0400, Hans Reiser wrote:
> >  > > >
> >  > > >     Making the server stateless is wrong
> >  > > >
> >  > > > why?
> >  > >
> >  > > Because it leads to all the problems we have seen!  
> Why not have the client
> >  > > have an open file handle (the way Samba works and the 
> way the Unix file
> >  > > system API works)?  Then when the server goes down the 
> client sends a request
> >  > > to open the file again...
> >
> > If you have 10000 clients each opening 100 files you got 1e6 opened
> > files on the server---it wouldn't work. NFS was designed to 
> be stateless
> > to be scalable.
> 
> Every existing file has at least one name (or is member of 
> the hidden to-be-deleted-directory, and so has
> a name, too), and an object_id. Suppose the object_id is 32 
> bytes long. A virtual filedescriptor may be 4
> bytes long, some housekeeping metadata 28 bytes, so we will 
> have 64MB occupied in you scenario. Where's
> the problem? 80% of those 64MB can be swapped out.
> 
> >
> >
> >  > >
> >  > > >     making the readdir a multioperation act is wrong
> >  > > >
> >  > > > why? i have 3M directories... ar you saying clients 
> should read the
> >  > > > whole things at once?
> >  > >
> >  > > No.  findfirst()/findnext() is the correct way of 
> doing this.  Forcing the
> >  > > client to read through 3M directory entries to see if 
> "foo.*" matches
> >  > > anything is just wrong.  The client should be able to 
> ask for a list of file
> >  > > names matching certain criteria (time stamp, name, 
> ownership, etc).  The
> >  > > findfirst() and findnext() APIs on DOS, OS/2, and 
> Windows do this quite well.
> >  >
> >  > there is a fundamental conflict between having cookies, 
> shrinkable directories, and the ability to
> >  > find foo.* without reading the whole directory, all at 
> the same time.
> >  >
> >  > NFS V4 is designed by braindead twerps incapable of 
> layering software when designing it.
> >
> > Just cannot stand it. You mean that NFS v4 features 
> database in a kernel
> > too? (It's our insider joke.)
> 
> NFS should not be kernel-bound. The nfs server application 
> mimics the applications on the NFS clients. If
> this is not possible, something is wrong.
> 
> >
> >
> >  >
> >  > >
> >  > > If you have 3M directory entries then SMB should kick 
> butt over NFS.
> >  > >
> >  > > Also while we're at it, one of the worst things about 
> NFS is the issue of
> >  > > delete.  Because it's stateless NFS servers implement 
> unlink as "mv" and
> >  > > things get nasty from there...
> >  > >
> >  > > --
> >  > > http://www.coker.com.au/bonnie++/     Bonnie++ hard 
> drive benchmark
> >  > > http://www.coker.com.au/postal/       Postal SMTP/POP benchmark
> >  > > http://www.coker.com.au/projects.html Projects I am working on
> >  > > http://www.coker.com.au/~russell/     My home page
> >
> > Nikita.
> 
> Being "stateless" is only a weak way to implement 
> disconnected operation. If there was state (if the
> server could know that a client has a filedescriptor to a 
> file), the client could be informed that it's
> virtual file descriptors to the files to be deleted are 
> invalid now. This only fails if the network is
> down, so this is a disconnected operation problem.
> 
> By the way: if NFS was scaleable, why doesn't it allow every 
> handle from the server (like inode numbers,
> directory position cookies) to be of variable, dynamic, 
> server-determined size? This would be scaleable.
> 
> P.S.: Hans, how do you prevent object_id|inode reusing? Using 
> mount_id+generation counter per mount?
> 
> 
> 


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