Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 20 Oct 2004 14:43:58 +0200
From:      Alexander Leidinger <Alexander@Leidinger.net>
To:        Dan Nelson <dnelson@allantgroup.com>
Cc:        freebsd-current@freebsd.org
Subject:   Re: Read-only ReiserFS support for FreeBSD 5.x
Message-ID:  <1098276238.41765d8ebfc0b@netchild.homeip.net>
In-Reply-To: <20041019202047.GB83510@dan.emsphone.com>
References:  <417538B9.7070001@club-internet.fr> <41755FAF.8080300@colleduc.ee> <53515.208.4.77.15.1098213002.squirrel@208.4.77.15> <20041019202047.GB83510@dan.emsphone.com>

next in thread | previous in thread | raw e-mail | index | archive | help
Zitat von Dan Nelson <dnelson@allantgroup.com>:

> Journalled filesystems may guarantee that the filesystem will be
> consistent to a particular point in time, so if your editor updates
> (for example) rc.conf by creating a new copy named rc.conf.new,
> deleting rc.conf, then renaming the copy to rc.conf, you are guaranteed
> that either rc.conf or rc.conf.new will be in the filessytem after a
> crash.  With softupdates, you may lose both files.  I don't know if
> current journalled fses actually journal all writes like this (as
> opposed to just journalling what the OS decides to flush out of its
> cache), but they are much less likely to lose files the way softupdates
> can.

Sorry, this isn't true. Renaming a directory entry is an atomar operation.
Not only "man 2 rename" tells you about it, the softupdates algorithm
guarantees this too. If you move/rename an entry into another directory,
you may have both entries with the same content, but you won't loose both.

Bye,
Alexander.

-- 
http://www.Leidinger.net/     Alexander @ Leidinger.net: PGP ID = B0063FE7
http://www.FreeBSD.org/        netchild @ FreeBSD.org  : PGP ID = 72077137
This novel is not to be tossed lightly aside, but to be hurled with
great force.
		-- Dorothy Parker



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?1098276238.41765d8ebfc0b>