Linuxconf Kernel Configurator Module Gustavo Niemeyer This dialog allows you to configure many aspects of the linux kernel. You should be very careful with what you change here, since a bad option may crash your linux box and require that you boot as single user to correct your options. 1. Introduction 1.1. Missing options Note that maybe some of the options listed here are not available for you. It depends if your kernel is offering this functionality or not. 1.2. Default options When you set an option to default, it doesn't mean that as soon as you get out of linuxconf, this option will return to default value. Linuxconf has no way to know what are the default options of your kernel. It means that when you set an option to default, Linuxconf will not intervent in this option anymore, no matter what it is set to. Remember that kernel options are usually set in the /proc file system and, as this file system is mapped in memory, everything will be reset when you shutdown your machine. 2. Options Most of these descriptions were extracted from the kernel documentation. 2.1. File system 2.1.1. Max. file handles This value denotes the maximum number of file handles that the Linux kernel will allocate. When you get a lot of error messages about running out of file handles, you might want to raise this limit. 2.1.2. Max. inode handles This value denotes the maximum number of inode handlers. This value should be 3 to 4 times larger than the value in "Max. file handles", since stdin, stdout, and network sockets also need an inode struct to handle them. If you regularly run out of inodes, you should increase this value. 2.1.3. Max. num. cached disk quota This value denotes the maximum number of cached disk quota entries. If the number of free cached disk quotas is very low and you have a large number of simultaneous system users, you might want to raise the limit. 2.1.4. Max. super block handlers Every mounted file system needs a super block, so if you plan to mount lots of file systems, you may want to increase these numbers. 2.2. General 2.2.1. Ctrl-alt-del When this option is disabled, ctrl-alt-del is trapped and sent to the ``init'' program to handle a graceful restart. However, when it is enabled, Linux's reaction to this key combination will be an immediate reboot, without syncing its dirty buffers. 2.2.2. Fair Scheduler Fair Scheduler is a kernel option that greatly improves kernel abilities to handle processes who try to monopolize the processor time. 2.2.3. Shared memory size (meg) This specify the largest shared memory segment usable. 2.2.4. Max processes This controls the maximum number of processes (or threads) available on the system. 2.3. Semaphores This controls the System V IPC semaphores. 2.3.1. Max semaphores per ID. 2.3.2. Max semaphore in system This value defaults to "Max IDs" multiply by "Max semaphore per ID". 2.3.3. Max oper. per system call 2.3.4. Max IDs Maximum number of IDs in the system. Each ID may control several semaphores. This is usually the value you want to increase.