Don't give fire to children!
bad bad bad!

 

 

 

-----Original Message-----
From: Wols Lists <antli...@youngman.org.uk>
To: u2-users <u2-users@listserver.u2ug.org>
Sent: Fri, Nov 30, 2012 10:36 am
Subject: Re: [U2] Things you shouldn't do.....


On 30/11/12 16:39, Cypress Support wrote:
> The &PH& file is a type 1 file(a directory).
> 
> On AIX: When you write the record back to the directory, the inode is
> changed to point the the new disk location of the new file. The old file
> is still update(output for phantom) until the file is closed, then AIX
> removes it.   I'm sure this is the same on Linux/all UNIX distros, never
> tested.

Spot on.

IF UV does a "delete then rewrite" this is what's happened. Unlike in
many other systems, nix treats the directory entry and the file as
separate entities rather than different parts of the same. So UV would
have deleted the directory entry and created a new file identical to the
old one. But the phantom will continue writing to the old file. It will
be garbage-collected when the phantom terminates.

It is possible to recover it, but don't ask me how. You can ask the
system which processes have which files open and it will give you the
inodes. You can then relink that file somehow.

Off-topic - I make a lot of use of this tactic to save disk space - I
store all my digital photos in a "secure area", and then link them into
my and my wife's home directories so we both see the same file. And
because I use hard links, moving the "original" file doesn't break the
links. If you do an "ls -al" in a directory, one of the columns is the
number of links to the inode - do hard linking and you'll see this climb
above 1. Just don't hard-link a directory - I gather it can be done, but
an rm is likely to make a mess of your files ...
> 
> James
> 
Cheers,
Wol
_______________________________________________
U2-Users mailing list
U2-Users@listserver.u2ug.org
http://listserver.u2ug.org/mailman/listinfo/u2-users

 
_______________________________________________
U2-Users mailing list
U2-Users@listserver.u2ug.org
http://listserver.u2ug.org/mailman/listinfo/u2-users

Reply via email to