From owner-freebsd-arch Mon Mar 11 8:22:50 2002 Delivered-To: freebsd-arch@freebsd.org Received: from harrier.prod.itd.earthlink.net (harrier.mail.pas.earthlink.net [207.217.120.12]) by hub.freebsd.org (Postfix) with ESMTP id 7FA4937B402 for ; Mon, 11 Mar 2002 08:22:46 -0800 (PST) Received: from pool0620.cvx22-bradley.dialup.earthlink.net ([209.179.200.110] helo=mindspring.com) by harrier.prod.itd.earthlink.net with esmtp (Exim 3.33 #1) id 16kSZE-0000TS-00; Mon, 11 Mar 2002 08:22:33 -0800 Message-ID: <3C8CD9B8.53D6B36F@mindspring.com> Date: Mon, 11 Mar 2002 08:22:16 -0800 From: Terry Lambert X-Mailer: Mozilla 4.7 [en]C-CCK-MCD {Sony} (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Garance A Drosihn Cc: Poul-Henning Kamp , Harti Brandt , arch@FreeBSD.ORG Subject: Re: Increasing the size of dev_t and ino_t References: <17497.1015840078@critter.freebsd.dk> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Garance A Drosihn wrote: > At 10:47 AM +0100 3/11/02, Poul-Henning Kamp wrote: > >(Sorry, I confused st_dev and st_rdev earlier). > > > >Ok, I think we are on the same page now. > > > >I don't think any of the stuff headed for -current would give > >you trouble in this respect. Just because we _can_ assign a > >random st_dev doesn't mean we will shoot ourselves in the foot > >by doing so :-) > > Given what we (RPI) have with our present AFS cell, I am not > sure how easy it will be to do this. If you follow my previous > description of AFS, you realize that RPI (by itself) has over > 33,000 unique AFS volumes. We also have users who will touch > a large percentage of those volumes by typing in a single 'find' > command. If FreeBSD comes up with a unique random number for > each volume as it is referenced, and it has to cache all the > mappings between unique-numbers and AFS-volumes (so it can > tell when the same AFS volume is found at a different pathname > in AFS space), then that strikes me as an unwieldy situation. Poul is a non-native English speaker, and this often leads to intepretation issues. The usage here is archaic English, and the "can"/"will" are paired, which isn't clear from the use of the predicate phrase "by doing so". You should read this as "Just because we _can_ ... doesn't mean we _will_ ...". > Also note that the >33,000 number is only for the AFS cell at > RPI, and the way AFS works any single workstation can be mounting > volumes from more than 150 different AFS cells. AFS is trying > to create a world-wide distributed file system, and as such it > sees scaling issues that no one faces with NFS. This is a seperate problem. As you note, the number is already larger than 2^15; it's going to face scaling issues, no matter how you look at it, due to the single volume identification space. -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message