download

System Configuration—Tuning PerformanceThis will run a maximum of four simultaneous processes, which is most likely to useall available CPU resources, and consequently speed up the build process.It is advised that you do not to use this feature while building a kernel asit could break the build procedure.Traditionally FreeBSD uses 4BSD scheduler as the default scheduler. However, analternative scheduler called ULE has been also available since FreeBSD 5 and it hasimproved tremendously since then. It is now recommended to use ULE schedulerinstead of 4BSD scheduler in FreeBSD 7, and it will be the default scheduler in thenext release of FreeBSD. To use ULE scheduler, you should replace the SCHED_4BSDoption in your configuration file with following line:optionsSCHED_ULEDiskIn some cases, you may find the kernel's default limits very annoying. Especiallywhen you are running a busy server, you are likely to run out of "file descriptors" orface I/O limits.File limitsInfact everything, including actual files, network sockets, and so on, is treated asa file in UNIX. On a busy server, which has many network sockets or disk filesopen, the file descriptor tables will be exhausted and you will see file: table isfull in system's message buffer. The kern.maxfiles kernel variable contains themaximum number of file descriptor limit.# sysctl kern.maxfileskern.maxfiles: 8192# sysctl kern.maxfiles=16384kern.maxfiles: 8192 -> 16384I/O PerformanceThe new UFS2 file system which is available in FreeBSD 7 offers higher performanceas compared to the legacy UFS file system. However, you can still tweak your filesystem by using different mount options.[ 92 ]