Re: Linux 2.6.29

Jeff Garzik
2009-03-30T15:01:45Z

Mark Lord wrote:
> Ric Wheeler wrote:
>> Mark Lord wrote:
>>> Ric Wheeler wrote:
> ..
>>> The kernel can crash, and the drives, in practice, will still
>>> flush their caches to media by themselves. Within a second or two.
>>
>> Even with desktops, I am not positive that the drive write cache
>> survives a kernel crash without data loss. If I remember correctly,
>> Chris's tests used crashes (not power outages) to display the data
>> corruption that happened without barriers being enabled properly.
> ..
>
> Linux f/s barriers != drive write caches.
>
> Drive write caches are an almost total non-issue for desktop users,
> except on the (very rare) event of a total, sudden power failure
> during extended write outs.
>
> Very rare.

Heck, even I have lost power on a plane, while a laptop in laptop mode
was flushing out work. Not that rare.

> Yes, a huge problem for server farms. No question.
> But the majority of Linux systems are probably (still) desktops/notebooks.

But it doesn't really matter who is what majority, does it? At the
present time at least, we have not designated any filesystems "desktop
only", nor have we declared Linux a desktop-only OS.

Any generalized decision that hurts servers to help desktops would be
short-sighted. Robbing Peter, to pay Paul, is no formula for OS success.

Jeff