On Sun, 2008-08-31 at 12:00 -0700, Richard Elling wrote:
2. The algorithm *must* be computationally efficient.
We are looking down the tunnel at I/O systems that can
deliver on the order of 5 Million iops. We really won't
have many (any?) spare cycles to play with.
On Sun, 2008-08-31 at 15:03 -0400, Miles Nordin wrote:
It's sort of like network QoS, but not quite, because:
(a) you don't know exactly how big the ``pipe'' is, only
approximately,
In an ip network, end nodes generally know no more than the pipe size of
the first hop -- and in
bs == Bill Sommerfeld [EMAIL PROTECTED] writes:
bs In an ip network, end nodes generally know no more than the
bs pipe size of the first hop -- and in some cases (such as true
bs CSMA networks like classical ethernet or wireless) only have
bs an upper bound on the pipe size.
Hello Miles,
Sunday, August 31, 2008, 8:03:45 PM, you wrote:
dc == David Collier-Brown [EMAIL PROTECTED] writes:
MN dc one discovers latency growing without bound on disk
MN dc saturation,
MN yeah, ZFS needs the same thing just for scrub.
MN I guess if the disks don't let you tag
Richard Elling wrote:
[what usually concerns me is that the software people spec'ing device
drivers don't seem to have much training in control systems, which is
what is being designed]
Or try to develop safety-critical systems based on best effort instead
of first developing a clear and
Re Availability: ZFS needs to handle disk removal /
driver failure better
A better option would be to not use this to perform FMA diagnosis, but
instead work into the mirror child selection code. This has already
been alluded to before, but it would be cool to keep track of latency
over
dc == David Collier-Brown [EMAIL PROTECTED] writes:
dc one discovers latency growing without bound on disk
dc saturation,
yeah, ZFS needs the same thing just for scrub.
I guess if the disks don't let you tag commands with priorities, then
you have to run them at slightly below max
Miles Nordin wrote:
dc == David Collier-Brown [EMAIL PROTECTED] writes:
dc one discovers latency growing without bound on disk
dc saturation,
yeah, ZFS needs the same thing just for scrub.
ZFS already schedules scrubs at a low priority. However, once the
iops
