A swap partition can prevent several types of insufficient RAM symptoms, such as system instability, failing processes, and in severe cases, even reboots. All this depends largely on the network load and on FreshTomato's configuration. Some functions require much more RAM than others, and higher network traffic puts more load on the router and requires more RAM. USB storage is an excellent way to provide swap space.
This example assumes you are using an ARM or MIPS build with USB support, and USB support is already enabled. If you're not sure how to enable USB support, check the USB Support page.
For this example, we use a 16GB USB flash drive seen in the system as device sda.
This assumes your drive's device name is “sda” ! If it's not, remember to change these commands consistent with your drive's device name.
The echo 1000M statement below defines the size of the swap partition (in MB). You may adjust that according to your needs.
device=/dev/sda partition=$device'1' swappartition=$device'2' nvram set usb_automount="0" (echo o; echo n; echo p; echo 2; echo ; echo +1000M; echo t; echo 82; echo n; echo p; echo 1; echo ; echo ; echo w) | fdisk $device # Uncomment the preferred option here below: # mkfs.ext2 -L usb $partion # mkfs.vfat -n usb $partion mkswap -L swap $swappartion swapon swap mkdir /mnt/usb && mount /dev/sda1 /mnt/usb nvram set usb_automount="1"
From the Web interface, disable the Automount checkbox in the USB Support menu.
Then, logon via SSH or Telnet and delete any existing partitions:
fdisk /dev/sda o At this point your USB flash drive is unpartitioned. Now let's create the necessary partition table: n p 2 ENTER +1000M (Essentially 1 GB will used for swap) t 82 n p ENTER ENTER l (to verify) w (write to save changes and exit fdisk)
At this point, you should have two unformatted partitions on your flash drive:
Now, format the partitions. The ext2 filesystem is recommended for USB flash drives and ext3 for hard disks/SSDs.
mkfs.ext2 -L USB /dev/sda1 mkswap /dev/sda2
Now, mount the partitions:
swapon /dev/sda2 mkdir /mnt/sda1 && mount /dev/sda1 /mnt/sda1
You can now re-enable USB Automount on the USB Support menu.
The USB flash drive is now formatted. Your USB and NAS page settings should look like this:
Under Attached Devices, you should see something similar to this:
To verify the swap partition works properly, check the Overview menu. You should see details related to swap space: