[DRBD-user] Resizing without active peer

Michael Rhyner michael.rhyner at stepping-stone.ch
Mon Sep 15 11:23:01 CEST 2008

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


I tried to resize the volume the way you told me with a 2 TB EVMS 
volume, and there was 30 GB free space that I want to add:

yesterday's kernel log:
Sep 10 11:36:13 s_kernel at filer-03 kernel: drbd2: 2052 GB (537902550 
bits) marked out-of-sync by on disk bit-map.

- first disconnected the ressource with:
drbdadm disconnect r2

- resized underlying volume within EVMS by 30 GB

- then executed:
drbdadm resize r2

- then connected again:
drbdadm connect r2

drbd2: 2052 GB (537902550 bits) marked out-of-sync by on disk bit-map.
drbd2: Writing meta data super block now.
drbd2: conn( StandAlone -> Unconnected )
drbd2: Starting receiver thread (from drbd2_worker [28729])
drbd2: receiver (re)started
drbd2: conn( Unconnected -> WFConnection )

There doesn't seem to happen anything...

Lars, thank you anyway.

Michael Rhyner

Lars Ellenberg schrieb:
> On Tue, Sep 09, 2008 at 11:51:24AM +0200, Michael Rhyner wrote:
>> Hello drbd users
>> I use DRBD, but have one storage system at the moment, it's planned to  
>> add the peer later, so we set up our logical volumes alrady on top of  
>> DRBD. We use a stacked setup, means underlying EVMS - DRBD - EVMS.
>> Now we would like to enlarge the DRBD space of resource "r2" by  
>> enlarging the underlaying EVMS volume.
>> cat /proc/drbd shows this:
>>  2: cs:WFConnection st:Primary/Unknown ds:UpToDate/DUnknown C r---
>>     ns:0 nr:0 dw:40807895 dr:12598 al:10086 bm:6253 lo:0 pe:0 ua:0 ap:0
>> 	resync: used:0/61 hits:0 misses:0 starving:0 dirty:0 changed:0
>> 	act_log: used:0/3833 hits:40796120 misses:10124 starving:0 dirty:38  
>> changed:10086
>> So we resize the underyling EVMS volume from 100 GB to 150 GB, then  
>> execute this command: drbdadm resize r2
>> As assumed, the drbd disk device shows still only 100 GB within EVMS.
>> I know that connection state should be "Connected", but is there a  
>> possibility to circumvent this situation and nevertheless enlarge the  
>> volume on-line, because I don't have a peer yet, and therefore I  
>> wouldn't risk to render something inconsistent.
> should work if you first "disconnect".
> I expect a "drbdadm resize" to pickup the new device size
> on a "StandAlone" node as well.
> as long as it has never seen the peer so far,
> it should even propagate the new size to upper layers,
> so the stacked EVMS should notice.
> if drbd has ever seen its peer, it has stored the peers lower level
> device size, so it will refuse to grow larger than that for obvious
> reasons, unless you connect it to the peer, and the peer confirms
> that it could handle a larger device size now.

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