-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 At some point hitherto, [EMAIL PROTECTED] hath spake thusly: > On 25 Jun 2002, at 9:18am, Kevin D. Clark wrote: > >> Ever. NFS's history of piss-poor file locking means a shared mailspool is > >> a recipe for disaster in any kind of heterogeneous environment. > > > > NFS file locking has gotten better over the years. > > Right. The problem is that not every OS release has kept pace, and that > not every computer in the world is running an OS release that has kept pace.
Quite true, and a very good point. > And, since this is a Linux list, and Linux for a long time had the worst NFS > implementation in the world, I think these concerns are justified. Not so much anymore, if the application does the right thing. If you do POSIX locking (i.e. fcntl()) over NFS on Linux, using 2.4 kernels, and recent versions of nfsutils, it does work reliably. The traditional form of locking which historically has worked for all cases (namely the link()ing to a unique lock file) does NOT work reliably on Linux over NFS, because of a race condition. It should work reliably if and only if the server and clients are configured to use synchronous I/O, which is rarely the case in my experience. The default is not to use it, to improve performance, and so it goes largely unused. However, Last I'd read (in the man page for open(), I believe) there's still a race condition in the kernel that prevents this from being reliable. > > > Maildir format works just fine over NFS, no locking required. > > Okay, that's a good point. These concerns only apply to the admittedly > lame but unfortunately common Berkley mbox format. And other formats that save multiple messages per file, of which mbox is not the only one. But there are still the security implications, unless you take root access away from people's desktops. - -- Derek Martin [EMAIL PROTECTED] - --------------------------------------------- I prefer mail encrypted with PGP/GPG! GnuPG Key ID: 0x81CFE75D Retrieve my public key at http://pgp.mit.edu Learn more about it at http://www.gnupg.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE9GLfNdjdlQoHP510RAotdAKCQxA8vfCLxgCJH93NAHGsci/JSWACfeHe4 NA2kGL2NedkIv2jJGP8n7gw= =H6P7 -----END PGP SIGNATURE----- ***************************************************************** To unsubscribe from this list, send mail to [EMAIL PROTECTED] with the text 'unsubscribe gnhlug' in the message body. *****************************************************************
