Mike, As far as I know only Hitachi is using such a huge chunk size :
"So each vendor’s implementation of TP uses a different block size. HDS use 42MB on the USP, EMC use 768KB on DMX, IBM allow a variable size from 32KB to 256KB on the SVC and 3Par use blocks of just 16KB. The reasons for this are many and varied and for legacy hardware are a reflection of the underlying hardware architecture." http://gestaltit.com/all/tech/storage/chris/thin-provisioning-holy-grail-utilisation/ Also, here Hu explains the reason why they believe 42M is the most efficient : http://blogs.hds.com/hu/2009/07/chunk-size-matters.html He has some good points in his arguments. Regards, sendai -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss