[DRBD-user] How long does it take OOS to clear

[G C]

Would any of these values being changed help or would it need to be the
actual speed between the two nodes that needs to be increased?

disk {
        on-io-error detach;
        c-plan-ahead 10;
        c-fill-target 24M;
        c-min-rate 80M;
        c-max-rate 720M;
    }
    net {
        protocol A;
        max-buffers 36k;
        sndbuf-size 1024k;
        rcvbuf-size 2048k;
    }

Thank you



On Mon, Oct 21, 2019 at 10:10 AM Digimer <lists at alteeve.ca> wrote:

> I assumed it wasn't paused, but that confirms it.
>
> Protocol A allows for out of sync to grow. It says "when the data in on
> the network buffer to send to the peer, consider the write complete". As
> such, data that hasn't made it over to the peer causes oos to climb. If
> you have a steady write rate that is faster than your transmit
> bandwidth, then seeing fairly steady OOS makes sense.
>
> To "fix" it, you need to increase the connection speed to the peer node.
> Or, less likely, if the peer's disk is slower than the bandwidth
> connecting it, speed up the disk write speed.
>
> In either case, what you are seeing is not a surprise, and it's not a
> problem with DRBD. The only other option is to use protocol C, so that a
> write isn't complete until it reaches the peer, but that will slow down
> the write performance of the primary node to be whatever speed you have
> to the peer. That's likely unacceptable.
>
> In short, you have a hardware/resource issue.
>
> digimer
>
> On 2019-10-21 12:19 p.m., G C wrote:
> > version: 8.4.10
> > Ran the resume-sync all and received:
> > 0: Failure: (135) Sync-pause flag is already cleared
> > Command 'drbdsetup-84 resume-sync 0' terminated with exit code 10
> >
> > Protocol used is 'A', our systems are running on a cloud environment.
> >
> >
> >
> >
> > On Mon, Oct 21, 2019 at 9:09 AM Digimer <lists at alteeve.ca
> > <mailto:lists at alteeve.ca>> wrote:
> >
> >     8.9.2 is the utils version, what is the kernel module version?
> >     (8.3.x/8.4.x/9.0.x)?
> >
> >     It's possible something paused sync, but I doubt it. You can try
> >     'drbdadm resume-sync all'. The oos number should change constantly,
> any
> >     time a block changes it should go up and every time a block syncs it
> >     should go down.
> >
> >     What protocol are you using? A, B or C?
> >
> >     digimer
>
>
> --
> Digimer
> Papers and Projects: https://alteeve.com/w/
> "I am, somehow, less interested in the weight and convolutions of
> Einstein’s brain than in the near certainty that people of equal talent
> have lived and died in cotton fields and sweatshops." - Stephen Jay Gould
>
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