From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom McNeal Subject: Re: nfs support of FAT file systems Date: Tue, 11 Mar 2003 20:39:00 -0800 Sender: nfs-admin@lists.sourceforge.net Message-ID: <3E6EB9E4.9000504@attbi.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Return-path: Received: from sccrmhc01.attbi.com ([204.127.202.61]) by sc8-sf-list1.sourceforge.net with esmtp (Exim 3.31-VA-mm2 #1 (Debian)) id 18sxzf-0002gX-00 for ; Tue, 11 Mar 2003 20:37:31 -0800 To: Eno Compton , NFS maillist Errors-To: nfs-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Id: Discussion of NFS under Linux development, interoperability, and testing. List-Unsubscribe: , List-Archive: Hi - Here is a more complete answer from Neil Brown, covering the various FAT file systems. I will be putting a discussion of this into the FAQ, since I think its an important issue to a lot of folks: NFS access to FAT filesystems works for simple cases, starting with the early 2.4 kernels, but if used extensively can cause grief. FAT file systems can be exported, but only those operations supported by that file system will be honoured. *Note* Operations such as "chown", "link", and "symlink" are not supported by these file systems, and will fail. Read/write/create etc., should be fine as long as the files remain relatively unchanged. The FAT filesystem layout does not contain enough information to create a lasting identity needed for NFS to create persistent filehandles. For example, If you take a file, rename it to another directory, trunctate it, and write new data to it, there is nothing stored in the filesystem that can be used to show that the resulting file is, in any sense, the "same" as the original file, and there is no way to find the new file given any details about the original file. Therefore, the Linux NFS server cannot guarantee that once you have opened a file, you can continue to have access to that file. If the file is modified in the ways given above, NFS may be unable to locate or identify the file correctly, and so may return ESTALE errors. This may happen if the fileserver is rebooted, or if the fileserver is under heavy memory pressure. The only fix which might be applied would require file handle changes, and would not completely solve the problem, and would be a lot of work, so it doesn't look likely at all. I hope this helps. Tom Eno Compton wrote: > I thank you, Tom, for your trouble. > Eno > > -----Original Message----- > From: trmcneal@attbi.com [mailto:trmcneal@attbi.com] > Sent: Monday, March 10, 2003 11:43 AM > To: Eno Compton > Subject: Re: nfs?? > > I believe that is correct. Linux will certainly allow fat32 mounts, but > exporting one is a different matter. I'll check to make sure. > > Regards - > > Tom > > -- > Tom McNeal > (650)906-0761(cell) > (650)964-8459(fax) > >>Don't know if it's proper to contact you directly. Hope so. Can't find an >>answer. >>I think nfs will not export a fat32 partition under linux. Is that correct? > >>Eno Compton >> > -- Tom McNeal (650)906-0761(cell) (650)964-8459(fax) Email: trmcneal@attbi.com ------------------------------------------------------- This SF.net email is sponsored by:Crypto Challenge is now open! Get cracking and register here for some mind boggling fun and the chance of winning an Apple iPod: http://ads.sourceforge.net/cgi-bin/redirect.pl?thaw0031en _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs