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SubjectRe: [ANNOUNCE] Ramback: faster than a speeding bullet
Pavel Machek wrote:
> Hi!
>
>>> Everyone who has write cache turned on for their hard drives is
>>> running in a mode similar to ramback anyway (except for when the file
>>> system is set to force writes to the platter, but that is rare).
>>> Admittedly, software crashes rarely cause the write cache to be lost,
>>> but hardware failures do, practically every time.
>> On the contrary - the hard disk cache is managed by the barrier logic in
>> the kernel, and the ordering even on failures is fairly predictable.
>
> Well, not even all modern hdds support barriers... It would be really
> nice to have _safe_ settings by default here...
>

The only really safe default is to disable the write cache by default or
possibly dynamically disable the write cache when barriers are not
supported by a drive. Both have a severe performance impact and I am not
sure that for most casual users it is a good trade.

ric


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