On 17/09/2013 15:13, Grant wrote: >>> Is multi-mirroring (3-disk RAID1) support without RAID0 common in >>> hardware RAID cards? >> >> Nope. Not at my pay grade, anyway. The only ones I know of are the >> Hewlett-Packard MSA/EVA, but they don't call it plain RAID1. They allow >> you to create virtual disk groups, though, so you can mirror a mirror to >> achieve the same effect. >> >> The only other place I've seen it in real life is Linux's mdraid. > > Thanks Michael. This really pushes me in the ZFS direction.
If you need another gentle push, ZFS checksums everything it does as it does it, so it catches data corruption that almost all other systems can't detect. And it doesn't have write holes either. A very good analogy I find is Google, and why Google decided to take the software/hardware route they did (it simplifies down to scalability). Hardware will break and at their scale it will do it three times a day. Google detects and works around this in software. ZFS's approach to how to store stuff on disk in an fs is similar to Google's approach to storing search data across the world. With the same benefit - take the uber-expensive hardware and chuck it. Use regular stuff instead and use it smart. -- Alan McKinnon alan.mckin...@gmail.com
