[DRBD-user] drbd and 10Gb/s network how to increase syncer rate beyond 100MB/s?

Maurits van de Lande M.vandeLande at VDL-Fittings.com
Tue Jan 31 17:46:29 CET 2012

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

I tested the link speed with iperf and on average I get 7 Gbit/s

With the c-plan-ahead option I was able to request I higher syncer rate. Unfortunately the rate is still limited to

Can Somebody confirm a syncer rate > 1Gbit/s when using drbd8.4?

Or should I switch back to drbd8.3?

[root at vmhost1a ~]# cat /proc/drbd
version: 8.4.1 (api:1/proto:86-100)
GIT-hash: 91b4c048c1a0e06777b5f65d312b38d47abaea80 build by dag at Build64R6, 2011-12-21 06:08:50
 0: cs:SyncTarget ro:Secondary/Secondary ds:Inconsistent/UpToDate C r-----
    ns:0 nr:0 dw:0 dr:20928000 al:0 bm:1277 lo:0 pe:8 ua:0 ap:0 ep:1 wo:b oos:1457787088
        [>....................] sync'ed:  1.5% (1423620/1444048)M
        finish: 3:31:45 speed: 114,728 (112,484) want: 409,600 K/sec

Best regards,

Maurits van de Lande

| Van de Lande BV. | Lissenveld 1 | 4941VK | Raamsdonksveer | the Netherlands |T +31 (0) 162 516000 | F +31 (0) 162 521417 | www.vdl-fittings.com |

-----Oorspronkelijk bericht-----
Van: drbd-user-bounces at lists.linbit.com [mailto:drbd-user-bounces at lists.linbit.com] Namens Maurits van de Lande
Verzonden: zondag 29 januari 2012 11:50
Aan: drbd-user at lists.linbit.com
Onderwerp: Re: [DRBD-user] drbd and 10Gb/s network how to increase syncer rate beyond 100MB/s?

thank you for your feedback.

I'll try the c-plan-head option.And test the link speed with iperf.

>Variable-rate synchronization is on by default in DRBD 8.4. I had to 
>set c-plan-head to 0 before I was able to change sync rate even 
>temporarily. More information can be found at 


Maurits van de Lande
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