Re: Disk write cache (Was: Hyper-Threading Vulnerability)

Jeff Garzik
2005-05-16T14:33:38Z

Matthias Andree wrote:
> On Sun, 15 May 2005, Mikulas Patocka wrote:
>
>
>>Note that disk can still ignore FLUSH CACHE command cached data are small
>>enough to be written on power loss, so small FLUSH CACHE time doesn't
>>prove disk cheating.
>
>
> Have you seen a drive yet that writes back blocks after power loss?
>
> I have heard rumors about this, but all OEM manuals I looked at for
> drives I bought or recommended simply stated that the block currently
> being written at power loss can become damaged (with write cache off),
> and that the drive can lose the full write cache at power loss (with
> write cache on) so this looks like daydreaming manifested as rumor.

Upon power loss, at least one ATA vendor's disks try to write out as
much data as possible.

Jeff