Messages in this thread | | | Date | Wed, 01 Apr 2009 17:41:22 +0200 | From | "Andreas T.Auer" <> | Subject | Re: Linux 2.6.29 |
| |
On 01.04.2009 14:53 Chris Mason wrote: > On Wed, 2009-04-01 at 10:55 +1100, Dave Chinner wrote: > >> If you crash while rsync is running, then the state of the copy >> is garbage anyway. You have to restart from scratch and rsync will >> detect such failures and resync the file. gnome/kde have no >> mechanism for such recovery. >> > If this were the recovery system they had in mind, then why use rename > at all? They could just as easily overwrite the original in place. >
It is not a recovery system. The renaming procedure is almost atomic with e.g. reiser or ext3 (ordered), but simple overwriting would always leave a window between truncating and the complete rewrite of the file.
> Using rename implies they want to replace the old with a complete new > version. > > There's also the window where you crash after the rsync is done but > before all the new data safely makes it into the replacement files. >
Sure, but in that case you have only lost some of your _mirrored_ data. The original will usually be untouched by this. So after the restart you just start the mirroring process again, and hopefully, this time you get a perfect copy.
In KDE and lots of other apps the _original_ config files (and not any copies) are "overlinked" with the new files by the rename. That's the difference.
Andreas
| |