Date: Fri, 24 Mar 2000 14:18:20 -0500 From: "Troy Settle" <troy@picus.com> To: "Eric J. Schwertfeger" <ejs@bfd.com> Cc: <freebsd-questions@FreeBSD.ORG> Subject: RE: filesystem full? Message-ID: <BPEOKDIIGLACIBFDFLEPMEGKCAAA.troy@picus.com> In-Reply-To: <Pine.BSF.4.10.10003241106100.85863-100000@harlie.bfd.com>
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Eric, Thanks for this explanation. It makes perfect sense. I'm still going to grumble though... it's the nature of it all :) -Troy ** -----Original Message----- ** From: Eric J. Schwertfeger [mailto:ejs@bfd.com] ** Sent: Friday, March 24, 2000 2:13 PM ** To: Troy Settle ** Cc: freebsd-questions@FreeBSD.ORG ** Subject: RE: filesystem full? ** ** ** On Fri, 24 Mar 2000, Troy Settle wrote: ** ** > ** > ** > Hmm... bad taste to reply to one's own posts... but, I need to make a ** > correction: ** > ** > ** > ** If a process dies out, the kernel should release all ** resources used by that ** > ** process. The only processes using the /var filesystem, are the ** > ** default system ** > ** processes. I can't make any claims otherwise. ** > ** > After re-reading other replies, this should read: ** > ** > If a process has a file open, the kernel should not allow a user ** or another ** > process to delete said file. ** ** According to unix filesystem semantics, deleting a file that is in use is ** perfectly legitimate, and changing this would in fact break software. ** ** A file is a set of blocks on the disk pointed to by an inode. A directory ** entry is a pointer to the inode. When you open a file, the inode is ** resolved and the filename itself is no longer used. The distinction ** becomes critical in cases like this, or when dealing with hard links, ** which are multiple directory entries for the same inode. ** ** Now, when you delete or rename a file, you're not affecting the inode, but ** the directory entry. However, the inode usage count gets decremented, and ** when it drops to zero, the inode and associated blocks are considered ** free. ** ** Now, in the case where a program has a file open, the inode usage doesn't ** drop to 0 until the program closes the filehandle. ** ** Am I being clear? I've explained this to people that I work with, but ** email is different (no feedback, no gestures, etc). ** ** It's a simple concept, but one that isn't expected, so most people trip ** over it their first time. ** ** To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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