[Linux-cluster] Parameter snapshot in vm.sh

[Dirk H. Schulz]

Hi Thomas,

Thomas Sjolshagen schrieb:
>
> Quoting "Dirk H. Schulz" <dirk.schulz at kinzesberg.de>:
>
>> Hi folks,
>>
>> I do not understand this as the virtual machine image is stored 
>> wherever it is configured in the virtual machine config file - and 
>> what does it have to do with snapshots (i. e. what is a "snapshot 
>> directory")?
>>
>
> The snapshot directory is the directory into which vm.sh will "virsh 
> save" the memory contents of the guest when shutting it down (when 
> use_virsh="1" at least). As I understand it, during rgmanager (or 
> clusvcadm -d) activities, the vm is saved to the snapshot directory 
> and restored from the file in that directory - if it exists.

Thanks for pointing to the right direction. I should have looked more 
deeply into vm.sh - you are right, it is used only in conjunction with 
use_virsh=1 so I can look up there what is done exactly (when I need it, 
at the moment it is all xm).
>
> Somewhat unrelated; I'd love to have a parameter that defines the 
> "stop" action as either "snapshot" or "shutdown". It takes a long time 
> to snapshot 10 guests to a gfs2 file system and the restore 
> functionality does a valiant effort, but the Linux kernel does not 
> seem to like being restored as of yet (the guest usually hangs after a 
> seemingly arbitrary amount of time). As a result, my innodb based 
> tables get a little cranky from the interruption/crash.
Is far as I can see in vm.sh the standard action is shutdown:

> case $1 in
>         start)
>                   validate_all || exit $OCF_ERR_ARGS
>                 do_start
>                 exit $?
>                 ;;
>         stop)
>                  validate_all || exit $OCF_ERR_ARGS
>              do_stop shutdown destroy
>              exit $?
>                 ;;
In the "do_stop" line the method is set as a parameter to the do_stop 
function (which hands it to the xm/virsh stop functions). If you need 
both you could seperate a vm-stop.sh and vm-snap.sh script and use 
relevant <vm-stop name=...> containers in cluster.conf (I did not test 
that but it should work like this, should it not?).

Dirk