[DRBD-user] drbd with existing file system ( and internal metadata).

Michael Haverkamp mhaverkamp at kcp.com
Wed Mar 9 16:49:52 CET 2005


Brett Bolen wrote:
> If he does not resize the filesystem, then do all syncs become
> full syncs?
> 
No.  I may have misunderstood your question when I gave my first answer. 
  I thought your concern was about destroying your data on accident.

> There is some reluctance that doing mkfs on the /dev/drbd0
> device ( or shrinking an existing partion) is necessary.
> 
Your only other option is external metadata.  i.e. Storing your metadata 
on another block device.

> Can you tell me what happens if we use 'internal metadata'
> with an existing file system ( ie one without the extra
> space at the end)?
> 
In an nutshell, your filesystem becomes corruct, and your metadata 
becomes corrupt.  This happens because your filesystem and drbd's 
metadata will both be trying to user the last 128MB of your disk, and 
thus stomping all over each other.

> 
> Thanks.
> 
> Michael Haverkamp wrote:
> 
>> Brett Bolen wrote:
>>
>>> I would like to use an existing file system as the source
>>> for a drbd pair.
>>>
>>> What will happen if I do use the existign partion ( without
>>> mkfs'ng it)?  How does it know what to sync?
>>>
>> Before it syncs anything, you must declare one system to be "primary". 
>> The other system will then sync all of its data from the primary.
>>
>>> What does 'shrink the filesystem' mean?  How do I do this?
>>
>>
>> man resize2fs   ( if using ext3 )
>> man resize_reiserfs    ( if using reiserfs )
>> etc.
>>
>>>
>>> Thanks.
>>>   b\375
>>>
>>> _______________________________________________
>>> drbd-user mailing list
>>> drbd-user at lists.linbit.com
>>> http://lists.linbit.com/mailman/listinfo/drbd-user
>>
>> > 
> 
> 
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-- 
Michael Haverkamp



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