[rhn-users] Adjusting swap space

[Corné Beerse]

Eric Van Steenbergen wrote:
> Hello all,
> 
>  
> 
> For some bizar reason swap space on one of our servers is set to 0.
> 
>  
> 
> [root at RHESPIRSCH etc]# free
> 
>              total       used       free     shared    buffers     cached
> 
> Mem:       1538852     227156    1311696          0      16948      99108
> 
> -/+ buffers/cache:     111100    1427752
> 
> Swap:            0          0          0
> 

Should be no problem, the system has about 1/3-rd of its core memory free. 
However, if there is swap, some pages can be swapped away to gain space for 
buffers and/or cache.

If you encounter problems and need (more) swap, just set it on with `swapon`. 
For example: `swapon -a` for all swapspace configured in "/etc/fstab".

If there is none configured, follow the swapon documentation (try `man swapon`) 
to configure either a swap partition (best) or a swapfile (for temporary swap).

btw: swap space can be max 2 GByte on a 32-bit system, I don't know how about 
64bits systems.

My swap line in /etc/fstab:
/dev/sda3	none	swap	sw	0 0
which makes the 3rd partition a swap partition. You can have more swap 
partitions, preferably all on different disks.



>  
> 
> On another server we have here with the same OS output is:
> 
>  
> 
> [root at rhbelgium root]# ls
> 
> anaconda-ks.cfg  ck.bash_profile  install.log  install.log.syslog  lic.txt
> 
> [root at rhbelgium root]# free
> 
>              total       used       free     shared    buffers     cached
> 
> Mem:       1025344    1003320      22024          0     227088     401564
> 
> -/+ buffers/cache:     374668     650676
> 
> Swap:      2338808      34944    2303864
> 
>  
> 
> Can anyone tell me what has gone wrong and what I can do/use to adjust 
> the swap space so that is back to normal? When I try to upgrade I get 
> the error that the system cannot access the rootvg/swap and the only 
> thing I can do is reboot. I checked /etc/fstab and they are identical.
> 

It is realy possible that `swapon -a` is somehow missed during boot. Just do it 
now and see the messages.


CBee


>  
> 
> Sincerely,
> 
>  
> 
> Eric Van Steenbergen
> 
> Network Facility Manager
> 
> Technical Field Engineer