[Ocfs2-users] 2 node cluster with shared LUN via FC

[Manuel Bogner]

sorry for the repost, but just saw that i mixed german and english...
here is the corrected version:



Hi,

I'm trying to create a cluster out of 2 nodes. Both systems share the
same LUN via FC and see it as /dev/sdd.

/dev/sdd has one partition

Disk /dev/sdd: 21.4 GB, 21474836480 bytes
64 heads, 32 sectors/track, 20480 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Disk identifier: 0xc29cb93d

   Device Boot      Start         End      Blocks   Id  System
/dev/sdd1               1       20480    20971504   83  Linux

which is formated with

  mkfs.ocfs2 -L ocfs2 /dev/sdd1


Here is my /etc/ocfs2/cluster.conf

node:
    ip_port = 7777
    ip_address = 10.0.0.168
    number = 0
    name = xen02a
    cluster = ocfs2

node:
    ip_port = 7777
    ip_address = 10.0.0.102
    number = 1
    name = xen02b
    cluster = ocfs2

cluster:
    node_count = 2
    name = ocfs2


Everything seems to be fine:

xen02a:~# /etc/init.d/o2cb status
Driver for "configfs": Loaded
Filesystem "configfs": Mounted
Stack glue driver: Loaded
Stack plugin "o2cb": Loaded
Driver for "ocfs2_dlmfs": Loaded
Filesystem "ocfs2_dlmfs": Mounted
Checking O2CB cluster ocfs2: Online
Heartbeat dead threshold = 31
  Network idle timeout: 30000
  Network keepalive delay: 2000
  Network reconnect delay: 2000
Checking O2CB heartbeat: Active

And mounting the fs on each node works fine:

/dev/sdd1 on /shared type ocfs2 (rw,_netdev,heartbeat=local)

Both nodes can ping each other.


xen02a:~# mounted.ocfs2 -d
Device                FS     UUID                                  Label
/dev/sdd1             ocfs2  55a9d0b0-050c-484f-9725-7788a3b9dde0  ocfs2

xen02b:~# mounted.ocfs2 -d
Device                FS     UUID                                  Label
/dev/sdd1             ocfs2  55a9d0b0-050c-484f-9725-7788a3b9dde0  ocfs2


Now the problem:

I first mount the device on node1:

 xen02a:~# mount -L ocfs2 /shared/
=> /dev/sdd1 on /shared type ocfs2 (rw,_netdev,heartbeat=local)
without any errors.

dmesg says:

[   97.244054] ocfs2_dlm: Nodes in domain
("55A9D0B0050C484F97257788A3B9DDE0"): 0
[   97.245869] kjournald starting.  Commit interval 5 seconds
[   97.247045] ocfs2: Mounting device (8,49) on (node 0, slot 0) with
ordered data mode.

xen02a:~# mounted.ocfs2 -f
Device                FS     Nodes
/dev/sdd1             ocfs2  xen02a

xen02a:~# echo "slotmap" | debugfs.ocfs2 -n /dev/sdd1
	Slot#   Node#
	    0       0


Now I mount the device on the second node:

xen02b:~# mount -L ocfs2 /shared/
=> /dev/sdd1 on /shared type ocfs2 (rw,_netdev,heartbeat=local)

[  269.741168] OCFS2 1.5.0
[  269.765171] ocfs2_dlm: Nodes in domain
("55A9D0B0050C484F97257788A3B9DDE0"): 1
[  269.779620] kjournald starting.  Commit interval 5 seconds
[  269.779620] ocfs2: Mounting device (8,49) on (node 1, slot 1) with
ordered data mode.
[  269.779620] (2953,0):ocfs2_replay_journal:1149 Recovering node 0 from
slot 0 on device (8,49)
[  270.950540] kjournald starting.  Commit interval 5 seconds

xen02b:~# echo "slotmap" | debugfs.ocfs2 -n /dev/sdd1
	Slot#   Node#
	    1       1

xen02b:~# mounted.ocfs2 -f
Device                FS     Nodes
/dev/sdd1             ocfs2  xen02b


So the first mount seems to be gone and any changes on the fs on that
node are not distributed.

At the moment I have no idea what this could be. I hope someone can help me.

regards,
Manuel