I know that in jaunty there are patches to prevent dataloss in ext4 however at the cost of performance.
Soh Kam Yung <[email protected]> wrote: >[http://www.h-online.com/open/Possible-data-loss-in-Ext4--/news/112821] > >===== >Possible data loss in Ext4 > >A bug report posted in the bug tracker for the next version of Ubuntu >9.04 (Jaunty Jackalope) describes a massive data loss problem when >using Ext4, the future standard file system for Linux, available as an >option when installing Ubuntu 9.04. The report describes a crash >occurring shortly after the KDE 4 desktop files had been loaded, >resulting in the loss of all of the data that had been created, >including many KDE configuration files. > >In a reply, Ext4 Developer Ted Ts'o explains the background of the >problem. Like other modern file systems, such as XFS, Ext4 implements >delayed allocation – writing new data can take up to 60 seconds. This >increases the performance and allows for optimisation of the data >organisation on the hard drive platter. > >The KDE and GNOME desktop applications often read and write a large >number of small files (for example, the configuration files for your >personal settings). If the system crashes there may not be enough time >for the data to be allocated and written to the hard drive – under >ext4, the files may be truncated. This is because of delayed >allocation. When a new file is created, the change is noted in the >journal, but the data isn't written to the disk for a new file for >anything between 45 and 150 seconds. The file system then catches up, >allocating space for the file and writing the data. The exact >technical details (which are critical system calls ftruncate() and >rename()) can be found in the Ext4 developer's answer to the bug >report. > >[...] >===== >-- >Soh Kam Yung >my Google Reader Shared links: >(http://www.google.com/reader/shared/16851815156817689753) >my Google Reader Shared SFAS links: >(http://www.google.com/reader/shared/user/16851815156817689753/label/sfas) > >_______________________________________________ >Slugnet mailing list >[email protected] >http://wiki.lugs.org.sg/LugsMailingListFaq >http://www.lugs.org.sg/mailman/listinfo/slugnet
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