Partially answering my own question here, as it occured to me that the zpool is scattering writes across the disc in 4k blocks, but hast has a minimum extent size of 2meg by default. Thats eems like a likely culprit for the 'dirty blocks' multiplcation I am seeing.
I shrunk down the extent size to 16k to see if that helped, and I now see a far smaller dirty block to written block ration, but also the write speed has now shrunk down even more to around 50k/s :-( Any advice on tuning this properly ? -pete. _______________________________________________ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
