Resume device. What is it?

[Nigel Henry]

I booted up F10 this morning, after fixing an selinux related problem 
yesterday, but the bootup stalled. I noticed an entry on the bootup messages, 
"unable to stat resume device". Not wishing to waste time on F10, as I'd had 
enough of that yesterday, I rebooted to Kubuntu Intrepid (on the same 
machine), and Intrepid hung for a few seconds with "waiting for resume 
device", then the bootup continued with no problems.

I googled "resume device", and there are a whole bunch of hits, with folks 
having various problems with it. It appears to be referencing "swap", but why 
resume device. I would have thought that, that description applied more to 
laptops, and my machine is a PC.

By the way, there is an entry for swap in /etc/fstab, which uses a UUID, 
rather than /dev/sda3 (which is the swap partition), but Gkrellm shows 0MB 
for swap, which indicates that swap is not on. That's on Intrepid, and fstab 
output is down a bit.

Ok. reboot again to Archlinux on the same machine, text flashed past with no 
delays on bootup, and Gkrellm shows swap as 2000M- 2000M free, which is 
correct, and /etc/fstab output is below (Arch doesn't use UUID's).

# /etc/fstab: static file system information
#
# <file system>        <dir>         <type>    <options>          <dump> 
<pass>
none                   /dev/pts      devpts    defaults            0      0
none                   /dev/shm      tmpfs     defaults            0      0


/dev/cdrom /mnt/cdrom   iso9660   ro,user,noauto,unhide   0      0
/dev/dvd /mnt/dvd   udf   ro,user,noauto,unhide   0      0
/dev/fd0 /mnt/fd0   vfat   user,noauto   0      0
/dev/sda3 swap swap defaults 0 0
/dev/sda7 / ext3 defaults 0 1
/dev/sda8 /home ext3 defaults 0 1

/dev/sdb1 /mnt/sdb1  vfat  auto,umask=0  0 0

The output from Kubuntu Intrepid's /etc/fstab is below.

# /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults        0       0
# /dev/sdb8
UUID=c71a76b0-5356-41e4-ab11-4b1c05cd5a6b /               ext3    
relatime,errors=remount-ro 0       1
# /dev/sdb9
UUID=3e395403-02e5-4e92-9c2e-d6f7695eeaba /home           ext3    relatime        
0       2
# /dev/sda3
UUID=a2bc95ec-5fe4-4651-9ca5-7027344141e3 none            swap    sw              
0       0
/dev/scd0       /media/cdrom0   udf,iso9660 user,noauto,exec,utf8 0       0

# Added by me
/dev/sdb1     /mnt/sdb1     vfat    auto,umask=0  0 0
/dev/sdb2     /mnt/sdb2     vfat    auto,umask=0  0 0

On the same machine, other distros show the following.

Kubuntu Hardy 8.04. Bootup hangs a bit with "waiting for resume device", and 
once booted up, fstab shows the swap partition as a UUID, rather than 
referencing /dev/sda3, and Gkrellm shows 0M for swap.

Gutsy Gibbon 7.10 on bootup shows "Activating swap", but Gkrellm shows 0M 
swap, and fstab is showing a UUID for the swap partition /dev/sda3.

Dapper Drake, which was upgraded from Breezy. No problems with swap here. 
Gkrellm shows 2000M-2000M free, and fstab output below.

# /etc/fstab: static file system information.
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults        0       0
/dev/sda5       /               ext3    defaults,errors=remount-ro 0       1
/dev/sda6       /home           ext3    defaults        0       2
/dev/sda1       /media/sda1     ext3    defaults        0       2
/dev/sda2       /media/sda2     ext3    defaults        0       2
/dev/sdb1       /media/sdb1     vfat    defaults        0       0
/dev/sda3       none            swap    sw              0       0
/dev/hda        /media/cdrom0   udf,iso9660 user,noauto     0       0
/dev/fd0        /media/floppy0  auto    rw,user,noauto  0       0

/dev/sdb1       /mnt/sdb1       vfat    auto,umask=0    0       0
/dev/sdb2       /mnt/sdb2       vfat    auto,umask=0    0       0


Again, as in the Archlinux install, no UUID's are involved specifically for 
the swap partition /dev/sda3, and Gkrellm displays the swap as 2000M-2000M 
free.

I suppose the question has to be put, that Gkrellm cannot see the swap 
partition when UUID's are involved, rather than a direct reference to the 
swap partition /dev/sda3, where Gkrellm shows swap.

Is there any command I can try, to see if swap is actually on, where Gkrellm 
cannot detect any swap when UUID's for the swap partition are involved?

Alternatively, could I simply comment out the line in /etc/fstab, where swap 
is referencing a UUID, and replace it with a line referencing /dev/sda3 as 
the swap partition?

Apologies for the long post.

Nigel.