[DRBD-user] why does drbd 8.2.7/8.2.8 take so long to sync

[Brian R. Hellman]

FYI, you can type: watch -n1 cat /proc/drbd
That will "watch" the command instead of having to continually run the
same command manually.


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Raoul Bhatia [IPAX] wrote:
> hi,
> 
> i repeatetly hit "cat /proc/drbd" to witness that drbd is not syncing
> as fast as expected:
> 
>  > root at wc01 /etc # cat /proc/drbd
>  > version: 8.2.7 (api:88/proto:86-88)
>  > GIT-hash: cd953e17c5eb47e7df835024fee4b13e5fcaa217 debian/rules build 
> by root at wc02, 2009-01-31 18:53:19
>  >  0: cs:SyncTarget st:Secondary/Primary ds:Inconsistent/UpToDate C r---
>  >     ns:0 nr:67800 dw:67800 dr:0 al:0 bm:278 lo:1 pe:0 ua:0 ap:0 ep:1 
> wo:b oos:20684
>  >         [==============>.....] sync'ed: 77.3% (20684/88484)K
>  >         finish: 0:01:43 speed: 132 (4,520) K/sec
>  >  1: cs:Connected st:Secondary/Primary ds:UpToDate/UpToDate C r---
>  >     ns:0 nr:11552 dw:11552 dr:0 al:0 bm:19 lo:0 pe:0 ua:0 ap:0 ep:1 
> wo:b oos:0
>  > root at wc01 /etc # cat /proc/drbd
>  > version: 8.2.7 (api:88/proto:86-88)
>  > GIT-hash: cd953e17c5eb47e7df835024fee4b13e5fcaa217 debian/rules build 
> by root at wc02, 2009-01-31 18:53:19
>  >  0: cs:SyncTarget st:Secondary/Primary ds:Inconsistent/UpToDate C r---
>  >     ns:0 nr:67800 dw:67800 dr:0 al:0 bm:301 lo:1 pe:0 ua:0 ap:0 ep:1 
> wo:b oos:20684
>  >         [==============>.....] sync'ed: 77.3% (20684/88484)K
>  >         finish: 0:02:09 speed: 104 (4,520) K/sec
>  >  1: cs:Connected st:Secondary/Primary ds:UpToDate/UpToDate C r---
>  >     ns:0 nr:11552 dw:11552 dr:0 al:0 bm:19 lo:0 pe:0 ua:0 ap:0 ep:1 
> wo:b oos:0
>  > root at wc01 /etc # cat /proc/drbd
>  > version: 8.2.7 (api:88/proto:86-88)
>  > GIT-hash: cd953e17c5eb47e7df835024fee4b13e5fcaa217 debian/rules build 
> by root at wc02, 2009-01-31 18:53:19
>  >  0: cs:SyncTarget st:Secondary/Primary ds:Inconsistent/UpToDate C r---
>  >     ns:0 nr:67820 dw:67820 dr:0 al:0 bm:319 lo:0 pe:65 ua:0 ap:0 ep:1 
> wo:b oos:20664
>  >         [==============>.....] sync'ed: 77.3% (20664/88484)K
>  >         finish: 0:02:09 speed: 108 (4,236) K/sec
>  >  1: cs:Connected st:Secondary/Primary ds:UpToDate/UpToDate C r---
>  >     ns:0 nr:11552 dw:11552 dr:0 al:0 bm:19 lo:0 pe:0 ua:0 ap:0 ep:1 
> wo:b oos:0
>  > root at wc01 /etc # cat /proc/drbd
>  > version: 8.2.7 (api:88/proto:86-88)
>  > GIT-hash: cd953e17c5eb47e7df835024fee4b13e5fcaa217 debian/rules build 
> by root at wc02, 2009-01-31 18:53:19
>  >  0: cs:SyncTarget st:Secondary/Primary ds:Inconsistent/UpToDate C r---
>  >     ns:0 nr:67968 dw:67968 dr:0 al:0 bm:330 lo:1 pe:30 ua:0 ap:0 ep:1 
> wo:b oos:20516
>  >         [==============>.....] sync'ed: 77.3% (20516/88484)K
>  >         finish: 0:02:33 speed: 116 (3,996) K/sec
>  >  1: cs:Connected st:Secondary/Primary ds:UpToDate/UpToDate C r---
>  >     ns:0 nr:11552 dw:11552 dr:0 al:0 bm:19 lo:0 pe:0 ua:0 ap:0 ep:1 
> wo:b oos:0
> 
> now i waited for a couple of seconds - still not that good.
>  > root at wc01 /etc # cat /proc/drbd
>  > version: 8.2.7 (api:88/proto:86-88)
>  > GIT-hash: cd953e17c5eb47e7df835024fee4b13e5fcaa217 debian/rules build 
> by root at wc02, 2009-01-31 18:53:19
>  >  0: cs:SyncTarget st:Secondary/Primary ds:Inconsistent/UpToDate C r---
>  >     ns:0 nr:68140 dw:68140 dr:0 al:0 bm:345 lo:1 pe:0 ua:0 ap:0 ep:1 
> wo:b oos:20344
>  >         [===============>....] sync'ed: 81.9% (20344/88484)K
>  >         finish: 0:01:58 speed: 124 (3,784) K/sec
>  >  1: cs:Connected st:Secondary/Primary ds:UpToDate/UpToDate C r---
>  >     ns:0 nr:11552 dw:11552 dr:0 al:0 bm:19 lo:0 pe:0 ua:0 ap:0 ep:1 
> wo:b oos:0
> 
> waited again - now things start to look better.
>  > root at wc01 /etc # cat /proc/drbd
>  > version: 8.2.7 (api:88/proto:86-88)
>  > GIT-hash: cd953e17c5eb47e7df835024fee4b13e5fcaa217 debian/rules build 
> by root at wc02, 2009-01-31 18:53:19
>  >  0: cs:SyncTarget st:Secondary/Primary ds:Inconsistent/UpToDate C r---
>  >     ns:0 nr:87996 dw:87996 dr:0 al:0 bm:866 lo:1 pe:28 ua:0 ap:0 ep:1 
> wo:b oos:488
>  >         [===================>] sync'ed:100.0% (488/88484)K
>  >         finish: 0:00:01 speed: 232 (1,996) K/sec
>  >  1: cs:Connected st:Secondary/Primary ds:UpToDate/UpToDate C r---
>  >     ns:0 nr:11552 dw:11552 dr:0 al:0 bm:19 lo:0 pe:0 ua:0 ap:0 ep:1 
> wo:b oos:0
> 
> and now we're finally done
>  > root at wc01 /etc # cat /proc/drbd
>  > version: 8.2.7 (api:88/proto:86-88)
>  > GIT-hash: cd953e17c5eb47e7df835024fee4b13e5fcaa217 debian/rules build 
> by root at wc02, 2009-01-31 18:53:19
>  >  0: cs:Connected st:Secondary/Primary ds:UpToDate/UpToDate C r---
>  >     ns:0 nr:88504 dw:88504 dr:0 al:0 bm:996 lo:0 pe:0 ua:0 ap:0 ep:1 
> wo:b oos:0
>  >  1: cs:Connected st:Secondary/Primary ds:UpToDate/UpToDate C r---
>  >     ns:0 nr:11576 dw:11576 dr:0 al:0 bm:19 lo:0 pe:0 ua:0 ap:0 ep:1 
> wo:d oos:0
> 
> why is drbd talking that long to sync in this case?
> 
> cheers,
> raoul
>