Date: Thu, 10 May 2001 19:31:50 -0700 From: Kirk McKusick <mckusick@mckusick.com> To: Alfred Perlstein <bright@wintelcom.net> Cc: Terry Lambert <tlambert@primenet.com>, fs@FreeBSD.ORG Subject: Re: versioned files via snapshot evilness. Message-ID: <200105110231.TAA14475@beastie.mckusick.com> In-Reply-To: Your message of "Thu, 26 Apr 2001 11:10:11 PDT." <20010426111010.M18676@fw.wintelcom.net>
next in thread | previous in thread | raw e-mail | index | archive | help
Date: Thu, 26 Apr 2001 11:10:11 -0700 From: Alfred Perlstein <bright@wintelcom.net> To: Terry Lambert <tlambert@primenet.com> Cc: mckusick@FreeBSD.ORG, fs@FreeBSD.ORG Subject: Re: versioned files via snapshot evilness. * Terry Lambert <tlambert@primenet.com> [010426 10:46] wrote: > > I'm wondering if it might be possible to abuse the ffs snapshot > > stuff to do file versioning ala VMS. > > Not really, IMO. > > Versioning ala VMS requires kernel globbing, or amazingly > intrusive library modifications, coupled with a guarantee > by programmers that they will only use the preferred APIs > in their applications. > > Consider how you would make: > > fd = open( "foo", O_RDWR, 0); > > open version 17 of the file "foo", as opposed to an earlier version, > and how you would tag versions into the file names, without stealing > a character (e.g. ";"). Also note that "/" is valid in a UTF-8 > filename today, if it is part of a multibyte sequence (but FreeBSD > can not handle this). It would be nice if "foo" was the "HEAD" version of the file and each new open for write _could_ cause a foo;#ver or something to be created. I was asking more to find out the capabilities that snapshots brings versus the pre-existing limitations in the namespace code currently in place. More, can we snapshot individual files? -- -Alfred Perlstein - [alfred@freebsd.org] Represent yourself, show up at BABUG http://www.babug.org/ The way that snapshots are implemented, they only work for filesystems as a whole, not for individual files. Kirk To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200105110231.TAA14475>