That is incorrect. A UPS reduces the risk, but does not eliminate it.
nothing eliminate all risks.
But for most applications, you must have the write cache off,
and you need queuing (e.g. TCQ or NCQ) for performance. If
you have queuing, there is no need to turn the write cache
on.
did you tested the above claim? i have SATA drives everywhere, all in ahci
mode, all with NCQ active.
It is inexcusable that FreeBSD defaults to leaving the write cache on
for SATA & PATA drives. At least the admin can easily fix this by
adding hw.ata.wc=0 to /boot/loader.conf. The bigger problem is that
FreeBSD does not support queuing on all controllers that support it.
i must be happy as i never had a case of not seeing
adaX: Command Queueing enabled
on my machines.
_______________________________________________
freebsd-hackers@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-hackers
To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
