[DRBD-user] Resync Incredibly Slow

[Adrian Pascalau]

On Sun, Aug 19, 2018 at 1:39 AM, Eric Robinson <eric.robinson at psmnv.com> wrote:
>
> I’ve been using drbd for a decade, but this is my first experience with drbd 9.0.14. The resync is incredibly slow. Normally, resync takes a few seconds to a few minutes, but this is taking hours, advancing just a few hundredths of a percent every few seconds…
>

Hi Eric,

I am wondering, are you running drbd in physical hosts, or vitual machines?

I am in a worse situation with the same version of drbd, installed in
two up to date Centos 7 virtual machines running in an OpenStack pike
environment, with the same version of drbd installed from the elrepo
repository:

[root at drbd1 ~]# rpm -qa | grep kmod-drbd
kmod-drbd90-9.0.14-1.el7_5.elrepo.x86_64

I configured this environment last week Thursday, and believe it or
not, as of today sync is at 0.1%:

[root at drbd1 ~]# cat
/sys/kernel/debug/drbd/resources/drbd0/connections/drbd2.novalocal/0/proc_drbd
 0: cs:SyncSource ro:Secondary/Secondary ds:UpToDate/Inconsistent C r-----
    ns:6363972 nr:0 dw:0 dr:112432036 al:0 bm:0 lo:0 pe:[0;4] ua:52
ap:[0;0] ep:1 wo:1 oos:5242556
        [>....................] sync'ed:  0.1% (5116/5116)M
        finish: 127:25:23 speed: 0 (0 -- 0) K/sec
          0% sector pos: 0/10485368
        resync: used:1/61 hits:62 misses:2 starving:0 locked:0 changed:1
        act_log: used:0/1237 hits:0 misses:0 starving:0 locked:0 changed:0
        blocked on activity log: 0

Whatever I did, did not help, so finally I replicated the environment
in my laptop, in a VMware Workstation 11 environment, using the same
version of drbd, and in this case I have no issues.

This is my first experience with drbd, so I do not know how to
troubleshoot. Now I am thinking to look into older 8.x version, that
might be working better.

Regards,
Adrian