Monitor DRBD status

You can monitor the DRBD status by using one of two methods:

• service drbd status
• cat /proc/drbd

Sample output of the commands follows. These examples assume that you are running the commands on the primary (active) IBM® Netezza® host. If you run them from the standby host, the output shows the secondary status first, then the primary.

[root@nzhost1 ~]# service drbd status
drbd driver loaded OK; device status:
version: 8.2.6 (api:88/proto:86-88)
GIT-hash: 3e69822d3bb4920a8c1bfdf7d647169eba7d2eb4 build by root@nps22094, 2009-06-09 
16:25:53
m:res  cs         st                 ds                 p  mounted       fstype
0:r1   Connected  Primary/Secondary  UpToDate/UpToDate  C  /export/home  ext3
1:r0   Connected  Primary/Secondary  UpToDate/UpToDate  C  /nz           ext3
[root@nzhost1 ~]# cat /proc/drbd
version: 8.2.6 (api:88/proto:86-88)
GIT-hash: 3e69822d3bb4920a8c1bfdf7d647169eba7d2eb4 build by root@nps22094, 2009-06-09 
16:25:53
 0: cs:Connected st:Primary/Secondary ds:UpToDate/UpToDate C r---
    ns:15068 nr:1032 dw:16100 dr:3529 al:22 bm:37 lo:0 pe:0 ua:0 ap:0 oos:0
 1: cs:Connected st:Primary/Secondary ds:UpToDate/UpToDate C r---
    ns:66084648 nr:130552 dw:66215200 dr:3052965 al:23975 bm:650 lo:0 pe:0 ua:0 ap:0 oos:0

In the sample output, the DRBD states are one of the following values:

Primary/Secondary

The "healthy" state for DRBD. One device is Primary and one is Secondary.

Secondary/Secondary

DRBD is in a suspended or waiting mode. This usually occurs at boot time or when the nps resource group is stopped.

Primary/Unknown

One node is available and healthy, the other node is either down or the cable is not connected.

Secondary/Unknown

This is a rare case where one node is in standby, the other is either down or the cable is not connected, and DRBD cannot declare a node as the primary/active node. If the other host also shows this status, the problem is most likely in the connection between the hosts. Contact Netezza Support for assistance in troubleshooting this case.

The common Connection State values include the following values:

Connected

The normal and operating state; the host is communicating with its peer.

WFConnection

The host is waiting for its peer node connection; usually seen when other node is rebooting.

Standalone

The node is functioning alone because of a lack of network connection with its peer. It does not try to reconnect. If the cluster is in this state, it means that data is not being replicated. Manual intervention is required to fix this problem.

The common State values include the following values:

Primary

The primary image; local on active host.

Secondary

The mirror image, which receives updates from the primary; local on standby host.

Unknown

Always on other host; state of image is unknown.

The common Disk State values include the following values:

UpToDate

The data on the image is current.

DUnknown

This value is an unknown data state; usually results from a broken connection.