Re: Exposing FUA as alternative to DIOCCACHESYNC for WAPBL

[mlelstv%serpens.de@localhost (Michael van Elst)]

tls%panix.com@localhost (Thor Lancelot Simon) writes:

>When SCSI tagged queueing is used properly, it is not necessary to set WCE
>to get good write performance, and doing so is in fact harmful, since it
>allows the drive to return ORDERED commands as complete before any of the
>data for those or prior commands have actually been committed to stable
>storage.

Do you think that real world disks agree? WCE is often necessary to
get any decent performance and yes, data is not committed to stable
storage when the command returns (but there is a good chance that it
will be even when there is a power outage).


-- 
-- 
                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."