[DRBD-user] Node Maintenance

[Stuart Poulton]

Dear All,

I'm using drbd to provide disk storage to a number of xen domains
running on a pair of servers. 

Everything works fine, until I need to take one of the servers off-line
for maintenance work, this then causes the second system to reboot.

Clearly I've not understood part of the workings of drdb, and it's
configuration, can some one provide an insight into why this happens,
and what can be done to prevent it. Below is a copy of the drbd config
file.


global {
    usage-count yes;
}
common {
  syncer { rate 100M; }
}
resource xendomains {
  protocol C;
  handlers {
    pri-on-incon-degr "echo o > /proc/sysrq-trigger ; halt -f";
    pri-lost-after-sb "echo o > /proc/sysrq-trigger ; halt -f";
    local-io-error "echo o > /proc/sysrq-trigger ; halt -f";
    outdate-peer "/usr/sbin/drbd-peer-outdater";
  }
  startup {
  }
  disk {
    on-io-error   detach;
  }
  net {
    allow-two-primaries;
    after-sb-0pri disconnect;
    after-sb-1pri disconnect;
    after-sb-2pri disconnect;
    rr-conflict disconnect;
  }
  syncer {
    rate 100M;
    al-extents 257;
  }
  on x-host-2 {
    device     /dev/drbd0;
    disk       /dev/sdb1;
    address    10.1.1.111:7788;
    flexible-meta-disk  internal;
  }
  on x-host-3 {
    device    /dev/drbd0;
    disk      /dev/sdb1;
    address   10.1.1.112:7788;
    meta-disk internal;
  }
}
resource windows {
  protocol C;
  net {
	allow-two-primaries;
  }
  on x-host-2 {
    device     /dev/drbd1;
    disk       /dev/sdb2;
    address    10.1.1.111:7789;
    flexible-meta-disk  internal;
  }
  on x-host-3 {
    device    /dev/drbd1;
    disk      /dev/sdb2;
    address   10.1.1.112:7789;
    meta-disk internal;
  }
}
resource n-monitor {
  protocol C;
  net {
        allow-two-primaries;
  }
  on x-host-2 {
    device     /dev/drbd2;
    disk       /dev/sdb3;
    address    10.1.1.111:7790;
    flexible-meta-disk  internal;
  }
  on x-host-3 {
    device    /dev/drbd2;
    disk      /dev/sdb3;
    address   10.1.1.112:7790;
    meta-disk internal;
  }
}


Regards

Stuart