Storing System Binaries in AFS
| Chapter 2. Installing the First AFS Machine |

## Storing System Binaries in AFS

You can also choose to store other system binaries in AFS volumes, such as the standard UNIX programs conventionally located in local disk directories such as /etc, /bin, and /lib. Storing such binaries in an AFS volume not only frees local disk space, but makes it easier to update binaries on all client machines.

The following is a suggested scheme for storing system binaries in AFS. It does not include instructions, but you can use the instructions in Storing AFS Binaries in AFS (which are for AFS-specific binaries) as a template.

Some files must remain on the local disk for use when AFS is inaccessible (during bootup and file server or network outages). The required binaries include the following:

- A text editor, network commands, and so on

- Files used during the boot sequence before the afsd program runs, such as initialization and configuration files, and binaries for commands that mount file systems

- Files used by dynamic kernel loader programs

In most cases, it is more secure to enable only locally authenticated users to access system binaries, by granting the l (lookup) and r (read) permissions to the system:authuser group on the ACLs of directories that contain the binaries. If users need to access a binary while unauthenticated, however, the ACL on its directory must grant those permissions to the system:anyuser group.

The following chart summarizes the suggested volume and mount point names for storing system binaries. It uses a separate volume for each directory. You already created a volume called `sysname` for this machine's system type when you followed the instructions in Storing AFS Binaries in AFS.

You can name volumes in any way you wish, and mount them at other locations than those suggested here. However, this scheme has several advantages:

- Volume names clearly identify volume contents

- Using the `sysname` prefix on every volume makes it is easy to back up all of the volumes together, because the AFS Backup System enables you to define sets of volumes based on a string included in all of their names

- It makes it easy to track related volumes, keeping them together on the same file server machine if desired

- There is a clear relationship between volume name and mount point name

Volume Name | Mount Point
--- | ---
`sysname` | /afs/`cellname`/`sysname`
`sysname`.bin | /afs/`cellname`/`sysname`/bin
`sysname`.etc | /afs/`cellname`/`sysname`/etc
`sysname`.usr | /afs/`cellname`/`sysname`/usr
`sysname`.usr.afsws | /afs/`cellname`/`sysname`/usr/afsws
`sysname`.usr.bin | /afs/`cellname`/`sysname`/usr/bin
`sysname`.usr.etc | /afs/`cellname`/`sysname`/usr/etc
`sysname`.usr.inc | /afs/`cellname`/`sysname`/usr/include
`sysname`.usr.lib | /afs/`cellname`/`sysname`/usr/lib
`sysname`.usr.loc | /afs/`cellname`/`sysname`/usr/local
`sysname`.usr.man | /afs/`cellname`/`sysname`/usr/man
`sysname`.usr.sys | /afs/`cellname`/`sysname`/usr/sys

Storing AFS Documents in AFS |  | Enabling Access to Foreign Cells