Miles Nordin wrote: >>>>>> "re" == Richard Elling <[EMAIL PROTECTED]> writes: >>>>>> > > re> Mike, many people use this all day long and seem to be quite > re> happy. I think the slow death spiral might be overrated :-) > > I don't think it's overrated at all. People all around me are using > this dynamic_pager right now, and they just reboot when they see too > many pinwheels. If they are ``quite happy,'' it's not with their > pager. >
If you run out of space, things fail. Pinwheels are a symptom of running out of RAM, not running out of swap. > The pinwheel is part of a Mac user's daily vocabulary, and although > they generally don't know this, it almost always appears because of > programs that leak memory, grow, and eventually cause thrashing. They > do not even realize that restarting Mail or Firefox will fix the > pinwheels. They just reboot. > ...which frees RAM. > so obviously it's an unworkable approach. To them, being forced to > reboot, even if it takes twenty minutes to shut down as long as it's a > clean reboot, makes them feel more confident than Firefox unexpectedly > crashing. For us, exactly the opposite is true. > > I think dynamic_pager gets it backwards. ``demand'' is a reason *NOT* > to increase swap. If all the allocated pages in swap are > cold---colder than the disk's io capacity---then there is no > ``demand'' and maybe it's ok to add some free pages which might absorb > some warmer data. If there are already warm pages in swap > (``demand''), then do not satisfy more of it, instead let swap fill > and return ENOMEM. > You will get more service calls for failures due to ENOMEM than you will get for pinwheels. Given the large size of disks in today's systems, you may never see an ENOMEM. The goodness here is that it is one less thing that requires a service touch, even a local sysadmin service touch costs real $$. -- richard _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
