Recently we are trying to tune ZFS on a machine which runs on 256RAM memory.  Our current ZFS memory variables for the ARC are max 255Gb and min 64Mb.  A main issue that we face is that during high peak times getting workflows aborded with not enough memory. (there are several flows that need up to 55G memory)When tried to limit the max value to 4G we faced degradation with slow performance.Output of    uname -a  SunOS xxxxx 5.11 11.1 sun4v sparc sun4v   Publisher: solaris   Version: 0.5.11 (Oracle Solaris 11.1 SRU 1.4)   Build Release: 5.11      Branch: 0.175.1.1.0.4.0psrinfo -pv  The physical processor has 2 cores and 16 virtual processors (0-15)  The core has 8 virtual processors (0-7)  The core has 8 virtual processors (8-15)  SPARC-T4 (chipid 0, clock 2848 MHz)  I am looking forward a rule of thumb in order to configure the values min/max arc memory.Should the arc gets a fixed amount of memory  (min max the same) or should check the max memory per timeslot (h or 1/2h ) and go with that value added a cap of ~ +10%Edit 1It's an application server with informatica powervemter 9.6.1 installedOur current hit rate is above 96%
ZFS ARC memory tuning
solaris;memory;performance;zfs;zfs arc