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| Filesystem | Description |
| /proc | To simplify access to system information, the /proc filesystem was created to provide an intuitive interface. Although it appears to exist on your hard disk, it doesn't take up any actual space. Many programs rely on your having this capability in place, so be sure to include support for it. |
| NFS | The Network File System (NFS) support is needed if you intend to access remote filesystems through this standard protocol. For a server, this capability is a must. |
| SMB | This network protocol was developed for Windows for Workgroups (also known as LanManager). This capability is useful only if you need to have direct access to Windows 95 or NT files as part of your filesystem. For most people, this option should be tagged No. For a server, you might want to select Module for this option because you never know where you're going to have to connect your machine. |
| NCP | NetWare support is done through the NCP protocol. Like SMB, this capability isn't terribly useful for most people; however, if you are in the process of transitioning away from NetWare, selecting this option is a useful way to provide a seamless transition. |
| ISO9660 | The ISO9660 filesystem is necessary if you intend to use CD-ROMs because many CD-ROMs are encoded in this format. If you have a CD-ROM attached to your machine, be sure to select Yes for this option. |
| OS/2 HPFS | Support for the OS/2 filesystem, HPFS, is read-only under Linux. Most people should select No for this option. |
| System V and Coherent | These two filesystems are from very old versions of UNIX and are useful only as means of transitioning old data to new filesystems. Most people should select No for this option. |
| Amiga FFS | The Amiga support is still considered experimental code and should be used with caution. |
| UFS | UFS is available on several other UNIX systems, most notably Solaris and SunOS. (Under SunOS, it was known as 4.2.) The support for this filesystem is read-only. |
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| NOTE |
If you plan to access a filesystem over the network, you do not need to support the remote filesystem directly. You do need to support NFS, however. For example, if you intend to mount a disk residing on a Solaris system, you do not need UFS support, only NFS. |
The Quota support option on this submenu is for people who need to limit the amount of disk space being used by each user. Currently, this capability is supported only with the second extended filesystem (ext2).
The last option in this submenu is for Mandatory lock support. Typically, file locking is done at the application level; however, there is an attempt to force locks on all files with this feature. As of the 2.0.30 kernel, the additional software to support this feature isn't available, so do not enable this option unless you are certain as to what you are doing.
Character devices work in a different manner than block devices. Block devices are typically disks, tape drives, and so on that transfer data in large chunks. In contrast, character devices transfer only one byte of data at a time; hence, they are typically keyboards, mice, serial ports, and so on.
As its name implies, the Character devices submenu is for the configuration of character devices in the kernel. This configuration is usually for your mouse, serial ports, and parallel ports, but a few unusual devices fall under this category as well.
To get basic support for your serial ports, you need to set the Standard/generic serial support option to Yes or Module. Unless you have a specific serial card such as an 8-port card, you do not need any additional serial support.
If you plan to use your printer or connect to a network via PLIP, be sure to set Parallel printer support to Yes also.
Mouse support comes in two flavors. You can use serial mice or bus mice. If you use serial mice, you do not need to explicitly turn on the Mouse Support option because the Standard/Generic serial support covers this capability. If you use a bus mouse, you need to set Mouse Support (not serial mice) to Yes and indicate which particular mouse you have attached to the machine.
The remaining options in the Character devices submenu are unusual and often unused features or hardware. Unless you explicitly know that your system uses them, select No for these options.
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| NOTE |
Before you attempt to configure kernel support for your sound card, be sure you have the correct IRQ and I/O Base Memory address. |
To enable sound card support in the kernel, begin by selecting Yes for the first option for Sound card support in the Sound submenu. By doing so, you can select which sound card you have in your system.
After you select Yes for the appropriate sound card in your system, scroll down to the section for providing the appropriate IRQ, DMA, and Base I/O address information. Although the information required varies from card to card, you should be able to get this information from the manual or the on-card jumper settings.
Because the Linux kernel is available in source code form, many people have taken an interest in its underlying functionality for one reason or another. To facilitate these people, additional debugging information can be compiled into the kernel by selecting Yes for the Kernel profiling support option.
As part of the profiling support, many functions are invoked with the intention of trying to force them to fail. This capability is useful during development to ensure that all possible paths of execution are exercised and tested. The result is a kernel that is less stable; hence, unless you truly understand the hows and whys of the kernel, you should leave the Kernel profiling support option tagged No.
Configuring a kernel can be tricky. Be ready to spend some time learning the options and the effects each option has on others. You can easily misconfigure a kernel, so don't feel bad if integrating a new feature correctly takes a few tries. As with any learning endeavor, as you gain experience, you will be able to get the job done right more quickly and with less heartache.
After you set all your options, be sure to save the configuration and not just quit without saving. The options are then written to a file that is read as part of the compilation. Based on your selections, only what is necessary is compiled.
Now that you have a configured kernel, you are ready to compile it. In comparison, the entire process, known as building the kernel, is much easier than the configuration process.