[DRBD-user] mirror config questions for manual failover

[george young]

[drbd-0.6.10, Suse 8.2 x86 linux 2.4.20-4GB-SMP, 2 nodes, pvt 100Mb net]
I have two nodes, pig-app and pig-db.  Default config is that pig-app has
the active copy of /home(36GB), pig-db has /db(1GB), each DRBD mirrored to
the other.  If and *only if* an administrator decides that one node is
down, she runs a script on the remaining node to take over the other's
file system (and switch ip's around so users get the new host).  I'm
having trouble getting the right drbd commands for this script.  I also
see very slowww syncing time...  
Both are are reiser file systems.
There is a private 100Mbit ethernet between the two nodes.
I use the HA-Linux "IPaddr" script, but heatbeat is *not* enabled.

Here's my script for pig-app to grab the /db filesystem from pig-db:
------------------------------------------------------------
if ping -c 1 pig-db; then
    rsh -n pig-db /usr/local/etc/ha.d/resource.d/datadisk drbd_db stop &
    sleep 30
fi
/sbin/drbdsetup /dev/nb1 disconnect
/sbin/drbdsetup /dev/nb1 net 10.0.0.115:7789 10.0.0.114:7789 C
/usr/local/etc/ha.d/resource.d/datadisk drbd_db start
------------------------------------------------------------
I'm trying to assure that I don't get into a 2-hour long sync while
users are screaming.  After correcting the problem, I can revert
off-hours, so that time is not critical.
Does this script make sense?  How could it be better?

I am also frustrated that it takes 2 hours to sync 36G over a 100Mbit
private net.  That's a rate of about 5 Mbytes/sec.  Disks on both hosts
are fast hardware raids.  Am I missing something?

Below is my(common) drbd.conf:
------------------------------------------------------------
resource drbd_home {
  protocol = C
  fsckcmd  = fsck -p -y
  disk {
    disk-size = 36707364k
  }
  net {
    sync-min    = 500k
    sync-max    = 100M    # maximal average syncer bandwidth
    tl-size     = 5000  # transfer log size, ensures strict write ordering
    timeout     = 60    # 0.1 seconds
    connect-int = 10    # seconds
    ping-int    = 10    # seconds
  }
  on pig-app {
    device  = /dev/nb0
    disk    = /dev/rd/c0d0p5
    address = 10.0.0.115
    port    = 7788
  }
  on pig-db {
    device  = /dev/nb0
    disk    = /dev/rd/c0d2p1
    address = 10.0.0.114
    port    = 7788
  }
}
resource drbd_db {
  protocol = C
  fsckcmd  = fsck -p -y
  disk {
    disk-size = 1052184k
  }
  net {
    sync-min    = 500k
    sync-max    = 100M    # maximal average syncer bandwidth
    tl-size     = 5000  # transfer log size, ensures strict write ordering
    timeout     = 60    # 0.1 seconds
    connect-int = 10    # seconds
    ping-int    = 10    # seconds
  }
  on pig-app {
    device  = /dev/nb1
    disk    = /dev/rd/c0d0p3
    address = 10.0.0.115
    port    = 7789
  }
  on pig-db {
    device  = /dev/nb1
    disk    = /dev/rd/c0d0p1
    address = 10.0.0.114
    port    = 7789
  }
}

[I did really *try* to be concise here, sorry about the length...]
Thanks,
	George Young
-- 
"Are the gods not just?"  "Oh no, child.
What would become of us if they were?" (CSL)