Technical data

3. Base configuration
COMP_TYPE_ROOTFS Default setting: COMP_TYPE_ROOTFS=’xz’
This variable selects the compression method to be used for the RootFS archive. Possible
values are ’xz’, ’lzma’, and ’bzip2’.
COMP_TYPE_OPT Default setting: COMP_TYPE_OPT=’xz’
This variable selects the compression method to be used for the OPT archive. Possible
values are ’xz’, ’lzma’, and ’bzip2’.
POWERMANAGEMENT Default Setting: POWERMANAGEMENT=’acpi’
The kernel supports different flavours of power management: the somewhat aged APM
and the newer ACPI. This variable lets you choose which flavour is to be used. Possible
values are ’none’ (no power management), ’acpi’, and the two APM variants ’apm’ and
’apm_rm’. The latter uses a special processor mode before switching the router off.
FLI4L_UUID Default Setting: FLI4L_UUID=”
This variable contains an universally unique identifier (UUID) which is used to point to
a place where persistent data can be stored, e.g. on a USB stick. The UUID can be gener-
ated on any Linux system (e.g. on the fli4l router) by executing 'cat␣/proc/sys/kernel/random/uuid'.
Each execution of this command above produces a new UUID which you can use in
FLI4L_UUID variable. If you create a directory on a persistent medium by the name of
this UUID, this directory will be used to store configuration changes as well as persistent
run-time data (e.g. DHCP leases). However, the corresponding packages has to support
this persistence mechanism (see the documentation to check this). Typically, use ’auto’
for the according storage location, instead of a hard-coded path.
If fli4l already stored data using this mechanism before configuring an UUID and creating
the directory, this data can be found under /boot/persistent. In this case, you will have to
manually move the data to the new location. We advice that you generate and configure
the UUID at the very beginning, avoiding the migration later on.
Additionally, please note that MOUNT_BOOT=’rw’ is needed if the storage directory is located
on the /boot partition.
We suggest using the /data partition (with the UUID-named directory being a top-level
directory there) or an USB stick for the storage location of persistent configuration and
run-time data. The file systems allowed are VFAT or, if you use OPT_HD all read-
writable filesystems supported there.
IP_CONNTRACK_MAX Default Setting: IP_CONNTRACK_MAX=”
This variable enables you to change the maximum number of simultaneously existing
connections. Normally, a sensible value for this setting is computed automatically, based
on the amount of your router’s physical RAM. Table 3.2 shows the defaults used.
If you use file sharing programs behind or on the router and your router has only little
RAM, you will hit the maximum number of simultaneous connections fastly. This will
prevent further connections to be established.
This causes error messages as
ip_conntrack: table full, dropping packet
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