IMHO, whether a dedicated log device needs redundancy (mirrored), should be determined by the dynamics of each end-user environment (zpool version, goals/priorities, and budget).
If mirroring is deemed important, a key benefit of the DDRdrive X1, is the HBA / storage device integration. For example, to approach the redundancy of a mirrored DDRdrive X1 pair, a SATA Flash based SSD solution would require each SSD to have a dedicated HBA controller. As sharing an HBA between the two mirrored SSDs would introduce a single point of failure not existing in the X1 configuration. Even with dedicated HBAs, removing the need for SATA cables while halving both the controller count and data path travel will notably increase reliability. It should be mentioned, one plus for a mirrored Flash SSD with dedicated HBAs (no cache or write through) is the lack of required power protection. Thanks, Christopher George Founder/CTO www.ddrdrive.com -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
