[newman]

Right. Thanks. So, this way it works:

[root@kindle base-us]# dd if=/dev/zero of=/mnt/base-us/swapfile bs=1M count=64
64+0 records in
64+0 records out

[root@kindle base-us]# /mnt/us/busybox mkswap /mnt/base-us/swapfile      
Setting up swapspace version 1, size = 67104768 bytes
UUID=13f995a8-ad20-4457-af12-628d213a82bb

[root@kindle base-us]# /mnt/us/busybox swapon /mnt/base-us/swapfile 

[root@kindle base-us]# /mnt/us/busybox swapoff /mnt/base-us/swapfile 

[root@kindle root]# dmesg | tail
...
Adding 65528k swap on /mnt/base-us/swapfile.  Priority:-1 extents:1 across:65528k

[root@kindle root]# free -m
             total       used       free     shared    buffers     cached
Mem:           124        121          2          0         11         24
-/+ buffers/cache:         85         38
Swap:           63          0         63

I'll update the guide accordingly. EDIT: Done.