On Tue 2009-08-25 16:56:40, david@xxxxxxx wrote: > On Wed, 26 Aug 2009, Pavel Machek wrote: > >> There are storage devices that high highly undesirable properties >> when they are disconnected or suffer power failures while writes are >> in progress; such devices include flash devices and MD RAID 4/5/6 >> arrays. > > change this to say 'degraded MD RAID 4/5/6 arrays' > > also find out if DM RAID 4/5/6 arrays suffer the same problem (I strongly > suspect that they do) I changed it to say MD/DM. > then you need to add a note that if the array becomes degraded before a > scrub cycle happens previously hidden damage (that would have been > repaired by the scrub) can surface. I'd prefer not to talk about scrubing and such details here. Better leave warning here and point to MD documentation. >> THESE devices have the property of potentially corrupting blocks being >> written at the time of the power failure, > > this is true of all devices Actually I don't think so. I believe SATA disks do not corrupt even the sector they are writing to -- they just have big enough capacitors. And yes I believe ext3 depends on that. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
