> It is absolutely not the case that hardware RAID has across the board > lower > risk of data corruption, with or without caching. Caching usually > increases > speed, as you say. > > Take a look at this article if you want to be scared about data > corruption, > even when using hardware RAID: > http://storagemojo.com/2007/09/19/cerns-data-corruption-research/ > > Theoretically, ZFS has much better data integrity than other file > systems / > volume managers / RAID controllers because it checksums all data and > all > metadata, all the time. Nothing else (that I know of) does this.
This is really interesting. I have noticed bit errors occasionally, and I am unusually paranoid of such a thing. It's about 50x more common in my personal experience, with optical media than magnetic. And almost never on a healthy ethernet. I do checksum and validate things with almost obsessive compulsion. Especially installation & backup images. That being said, I didn't know ZFS checksums on the fly. I can only assume this hurts performance, likewise if there's a lack of hardware caching, but I also habitually use iozone to benchmark my raid systems. Typically dell sata disks with caching raid 5 controller. I haven't googled for iozone results on ZFS systems, but if anyone here has any such results, I'd be interested in comparing. _______________________________________________ bblisa mailing list [email protected] http://www.bblisa.org/mailman/listinfo/bblisa
