[Drbd-dev] Question About current uuid in drbd9

[Philipp Reisner]

Hi Sung-eun,

Only 63 bits are random. We encode the current role (Primary = 1)
into the lowest bit. When comparing the UUIDs the lowest bit
is ignored.

From top of my head, one of the auto-recovery-after-split-brain
policies looks at this bit.

This is normal behavior and expected.

best regards,
 phil

Am Mittwoch, 24. August 2016, 16:41:05 CEST schrieb Kim, Sung-eun:
> Hello,
> 
> 
> I have a question about current uuid in drbd9
> 
> After initial full-sync, primary's current uuid is one more than
> secondary's current uuid.
> 
> ex) from drbdadm get-gi r0
> 
> primary *0005F0D20002F86D*
> 
> :0000000000000000:0000000000000000:0000000000000000:1:1:1:0:0:0:1:0:0:0
> 
> secondary
> *0005F0D20002F86C*
> 
> :0000000000000000:0000000000000000:0000000000000000:1:1:0:0:0:0:1:0:0:0
> 
> But I changed primary's role to secondary , and again changed to primary.
> and replication volume disk I/O is processed.
> 
> At this point, primary's current uuid is equal to secondary's current
> uuid.(not one more than secondary's)
> 
> primary
> *0006A4E400035276*
> 
> :0000000000000000:0000000000000000:0000000000000000:1:1:1:0:0:0:1:0:0:0
> 
> secondary
> *0006A4E400035276*
> 
> :0000000000000000:0000000000000000:0000000000000000:1:1:0:0:0:0:1:0:0:0
> 
> Is this Bug? , or normal situation?(intended implementation in drbd9?).
> 
> Could you let me about this result?
> 
> Thanks.
> 
> 
> Best Regards,
> Sung-eun Kim
> 
> [image: 설명: logo]
> 
> Technical Research Center / DRBD Team
> 
> Principal Research Engineer
> 
> *Sung-eun Kim               sekim at mantech.co.kr <sekim at mantech.co.kr>*
> 
> 202 Fl, Seoulforest Kolon digital Tower, 308-4, Seongsudong 2ga,
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> 
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> 
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> 
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