From owner-freebsd-arch Sun Mar 31 18:12:16 2002 Delivered-To: freebsd-arch@freebsd.org Received: from mail.rpi.edu (mail.rpi.edu [128.113.22.40]) by hub.freebsd.org (Postfix) with ESMTP id E00B937B41F for ; Sun, 31 Mar 2002 18:12:11 -0800 (PST) Received: from [128.113.24.47] (gilead.acs.rpi.edu [128.113.24.47]) by mail.rpi.edu (8.12.1/8.12.1) with ESMTP id g312C8CL493732; Sun, 31 Mar 2002 21:12:09 -0500 Mime-Version: 1.0 X-Sender: drosih@mail.rpi.edu Message-Id: In-Reply-To: <200203312214.g2VMEWD07500@beastie.mckusick.com> References: <200203312214.g2VMEWD07500@beastie.mckusick.com> Date: Sun, 31 Mar 2002 21:12:13 -0500 To: Kirk McKusick From: Garance A Drosihn Subject: Re: UFS snapshots in current Cc: arch@FreeBSD.ORG Content-Type: text/plain; charset="us-ascii" ; format="flowed" X-Scanned-By: MIMEDefang 2.3 (www dot roaringpenguin dot com slash mimedefang) 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 At 2:14 PM -0800 3/31/02, Kirk McKusick wrote: >All of the above is basically correct. Your use of a snapshot >over a long period of time and in particular over a CVS update, >build world, and install world should not cause trouble (other >than perhaps a large amount of disk space being used). There >is no problem with rebooting, provided that the filesystem with >the snapshot is cleanly unmounted. I really think this snapshot capability is great. Combined with the huge disks we can buy these days, I think snapshots will be useful in many ways that we're not even thinking of yet. >I fixed one deadlock last January, but am aware of at least >one more that is still there. I have a fairly good idea on how >to fix it, but have not yet had the time to work on that fix. Okay, thanks. >On your final question about making a pax archive, if you make >an archive of the real filesystem, the snapshot will show up >on the archive as a file the size of the filesystem partition. >If you mount the snapshot and then make an archive of that >filesystem, then the snapshot(s) in the archive will show up >as zero length files. Hmm. Is there any way for a regular user-land process to tell if a given file is a snapshot? Something in the stat() info, or some other way to tell? I have no urgent need for it, but it seems like it would be useful. -- Garance Alistair Drosehn = gad@eclipse.acs.rpi.edu Senior Systems Programmer or gad@freebsd.org Rensselaer Polytechnic Institute or drosih@rpi.edu To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message