ZFS honesty

[Ivan Voras]

On 06/01/2008, Scott Long <scottl at samsco.org> wrote:

> I guess what makes me mad about ZFS is that it's all-or-nothing; either
> it works, or it crashes.  It doesn't automatically recognize limits and
> make adjustments or sacrifices when it reaches those limits, it just
> crashes.  Wanting multiple gigabytes of RAM for caching in order to
> optimize performance is great, but crashing when it doesn't get those
> multiple gigabytes of RAM is not so great, and it leaves a bad taste in
> my mouth about ZFS in general.

I agree with the sentiment. I don't know about its implementation, but
surely some kind of backout could have be implemented? I'm just
guessing here: maybe the problem is in M_NOWAIT - maybe there could be
a M_NOWAIT_BUT_ALLOW_NULL that would be safe to use in non-sleepable
code but could return NULL, which could be tested and the whole file
system request postponed...