[K12OSN] Deleting Swap Files

[Jim McQuillan]

Eric,

You could use "showmount -a" to show if the workstation has the
/var/opt/ltsp/swapfiles directory mounted.

Jim.


On Fri, 11 Mar 2005, Eric Harrison wrote:

>
> Eric Harrison wrote:
> >
> > There is probably a way to work-around this in any case.
> > Maybe something as simple as:
> >
> >     for terminal in `showmount | grep -v '/'`
> >     do
> >         if [ -f /var/opt/ltsp/swapfiles/${terminal}.swap ]
> >         then
> >             touch /var/opt/ltsp/swapfiles/${terminal}.swap
> >         fi
> >     done
> >     /usr/sbin/tmpwatch --ctime --atime --mtime 720 /var/opt/ltsp/swapfiles/
> >
> >
> > I'm going to sleep on it before I build a test package. In the meantime,
> > hopefully someone will come up with a bright idea on how to do this
> > safely ;-)
>
> After sleeping on it, chatting with Shahms King a while, and then taking
> a long lunch, here is the best I can come up with:
>
>
> cd /var/opt/ltsp/swapfiles/
> for ip in `ls *.swap 2>/dev/null | sed s/.swap$//g`
> do
>    netstat -nap 2>/dev/null | grep ${ip}: >/dev/null && touch ${ip}.swap
>    ping -c 1 -w 10 ${ip} &> /dev/null && touch ${ip}.swap
> done
> /usr/sbin/tmpwatch --ctime --atime --mtime 168 /var/opt/ltsp/swapfiles/
>
>
>
>
> This would prevent a swap file from being deleted if any one of the
> following were true:
>
>   * the terminal had written to the swap file sometime in the last week
>   * the terminal had a tcp connection to the server in the last week
>   * the terminal could be pinged sometime in the last week
>
>
> The corner-case in this scenario is fairly small. All of the following
> would have to true for an active swap file to be deleted:
>
>   * the terminal would have to be configured to use a different server
>     for NFS_SWAP than it uses for its XDM connection, the default is
>     that the NFS_SWAP server & the XDM server are the same.
>   * pings would have to be disabled on the network
>   * the terminal did not modify the swap file in the previous week
>
>
> That seems sane enough for me. But then I don't use NFS_SWAP and don't
> have to hear people scream when their terminals randomly crash ;-)
>
> Any other sanity checks I could add in?
>
> -Eric
>
>