[DRBD-user] Re: 8.0.6 Sync problem after updating kernel

Peter P GMX Prometheus001 at gmx.net
Sat Oct 13 00:54:51 CEST 2007

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

Thank you for your hint.

Of course I have mounted the device on Machine B in r/o mode in order 
not to loose data.

I am still curious how drbd is populating the changes on the file system 
on machine B:
- So drbd is populating the changes to machine B (example: new file on 
harddisk on B).
- The filesystem on B should be in a current state (example: new file on 
harddisk on B is really stored).
- But on the OS side ext3 is not aware of the changes (example: file is 
not present).
I can imagine that in a r/w environment this will create diffcilties.

But in r/o mode I should not be able to change the data - or? I am 
looking for a solution to have at least a limited access from B to the 
joint filesystem.

Lars Ellenberg schrieb:
> On Fri, Oct 12, 2007 at 08:56:39PM +0200, Peter P GMX wrote:
>> I am using ext3 filesystem on top of drbd - on top of lvm2 - on top of 
>> raid 1 hard disks.
>> "what exactly do you mean by "detach"?" 
>> I checked it again to be more precise. When I change data on machine A I 
>> have to unmount the drbd volume on machine B and then mount it again in 
>> order to refelect the changes.
>> The strange thing is that drbd tells me that everything is in sync, but in 
>> fact the filesystem isn't unless I mount and unmount.
> to use any one file system
> on more than one node at the same time,
> you need to use a network sharing file system (nfs, samba, etc.)
> or a cluster aware file system (GFS, OCFS, etc.).
> if you use ext3/reiserfs/xfs/ any "conventional" file system
> on drbd in "allow-two-primaries", concurrently accessing it
> >from both nodes at the same time, 
> it will not work.
> no, not even read-only.
> it may crash your machines,
> and it definetly will scramble your data.
> this is mentioned in the example config file,
> in the manpages, and in several other places.
> repeat.
>   ## you currently are actively scrambling your data. ##
>   ## you currently are actively scrambling your data. ##
>   ## you currently are actively scrambling your data. ##
> happy cleaning up.

More information about the drbd-user mailing list