Nochmal...Reiserfs hat kein Problem bei Stromausfällen. Das Dateisystem
bleibt konsistent.

You see, when you yank the power cord out of the wall, not all parts of the computer stop functioning at the same time. As the voltage starts dropping on the +5 and +12 volt rails, certain parts of the system may last longer than other parts. For example, the DMA controller, hard drive controller, and hard drive unit may continue functioning for several hundred of milliseconds, long after the DIMMs, which are very voltage sensitive, have gone crazy, and are returning total random garbage. If this happens while the filesystem is writing critical sections of the filesystem metadata, well, you get to visit the fun Web pages at http://You.Lose.Hard/.

[..]

Why doesn't ext3 get hit by this? Well, because ext3 does physical-block journaling. This means that we write the entire physical block to the journal, and only when the updates to the journal are committed do we write the data to the final location on disk. So, if you yank out the power cord, and inode tables get trashed, they will get restored when the journal gets replayed.

XFS and ReiserFS do what is called logical journaling. This means that if you modify the mod time of an inode, instead of writing the entire inode table block to the journal, they just write a note in the journal stating that "inode X now has a mod time of Y". This takes much less space, so you can pack many more journal updates into a single disk block.

[..]

The problem with logical journaling is that if you do have an unexpected power drop, and the storage system scribbles garbage on the inode table, there's no way to recover. In some cases, the only thing that is left to be done is mkfs and restore from backups. (Backups? You do keep backups, right?)

Ad e2fsck + ext3:

Du hast recht, im Normalbetrieb (auch bei unsauberen Shutdowns) ist kein fsck von Nöten, da sollte das Journal replaying reichen. Allerdings gibts Fälle (sehr große Block-Buffer zB im RAID-Controller [*]; kaputter RAM/CPU/Mainboard, kaputte Block devices) wo ein Check unausweichlich ist, da im FS dann inkonsistenzen Bestehen die durch einen Journal Replay nicht beheben werden können.

[*] Es gab tatsächlich RAID-Controller mit 64MB und mehr Write-Cache am Controller ohne Battery backup. Was glaubst du was passierte wenn das Ding direkt nach sehr schrebintensiven Tasks stromlos wurde?