ZFS: 'checksum mismatch' all over the place

[Kenneth Vestergaard Schmidt]

Kenneth Vestergaard Schmidt <kvs at pil.dk> writes:
> We've just put a 12x750 GB raidz2 pool into use, but we're seeing
> constant 'checksum mismatch' errors. The drives are brand new.

And now the pool failed :(

I'm very puzzled by the fact, that the 'checksum mismatch' errors seem
to occur at the same offset on multiple disks:

Aug 20 01:00:24 leibniz root: ZFS: checksum mismatch, zpool=pil path=/dev/da0 offset=58350080 size=512
Aug 20 01:00:24 leibniz root: ZFS: checksum mismatch, zpool=pil path=/dev/da1 offset=58350080 size=512
Aug 20 01:00:24 leibniz root: ZFS: checksum mismatch, zpool=pil path=/dev/da2 offset=58350080 size=512
Aug 20 01:00:24 leibniz root: ZFS: checksum mismatch, zpool=pil path=/dev/da3 offset=58350080 size=512

Aug 20 01:00:24 leibniz root: ZFS: checksum mismatch, zpool=pil path=/dev/da2 offset=38010880 size=512
Aug 20 01:00:24 leibniz root: ZFS: checksum mismatch, zpool=pil path=/dev/da3 offset=38010880 size=512
Aug 20 01:00:24 leibniz root: ZFS: checksum mismatch, zpool=pil path=/dev/da4 offset=38010880 size=512
Aug 20 01:00:24 leibniz root: ZFS: checksum mismatch, zpool=pil path=/dev/da5 offset=38010880 size=512
Aug 20 01:00:24 leibniz root: ZFS: checksum mismatch, zpool=pil path=/dev/da6 offset=38010880 size=512
Aug 20 01:00:24 leibniz root: ZFS: checksum mismatch, zpool=pil path=/dev/da7 offset=38010880 size=512
Aug 20 01:00:24 leibniz root: ZFS: checksum mismatch, zpool=pil path=/dev/da8 offset=38010880 size=512
Aug 20 01:00:24 leibniz root: ZFS: checksum mismatch, zpool=pil path=/dev/da9 offset=38010880 size=512
Aug 20 01:00:24 leibniz root: ZFS: checksum mismatch, zpool=pil path=/dev/da10 offset=38010880 size=512

Can anybody offer anything to help me with this? I'm pretty much at a
loss as to how I can find the cause of this.

-- 
Kenneth Schmidt
pil.dk