tested setting of MAXPHYS/BKVASIZE

[Wojciech Puchar]

for whose who use HDDs put in kernel config setting below.

makeoptions     CONF_CFLAGS="-DBKVASIZE=32768"
options         MAXPHYS=4194304


or RAID5 arrays with large stripe size higher value of MAXPHYS would make 
sense.

additionally bump vfs.hirunningspace and vfs.lorunningspace (in 
/boot/loader.conf or sysctl.conf)

i have

vfs.hirunningspace=50000000
vfs.lorunningspace=35000000


it should be at least few times MAXPHYS