DataKeeper for Linux Troubleshooting

Deleting a DataKeeper resource will not delete the NetRAID device if the NetRAID device is mounted. You can manually unmount the device and delete it by executing:

mdadm –S <md_device> (cat /proc/mdstat to determine the <md_device>).

This is a “split-brain” scenario that can be caused by a temporary communications failure. After communications are resumed, both systems assume they are primary.

DataKeeper will not resync the data because it does not know which system was the last primary system. Manual intervention is required.

If not using a bitmap:

You must determine which server was the last backup, then take the resource out of service on that server. DataKeeper will then perform a FULL resync.

If using a bitmap (2.6.18 and earlier kernel):

You should take both resources out of service, starting with the original backup node first. You should then dirty the bitmap on the primary node by executing: $LKROOT/lkadm/subsys/scsi/netraid/bin/bitmap –d /opt/LifeKeeper/bitmap_filesys

(where /opt/LifeKeeper/bitmap_filesys is the bitmap filename). This will force a full resync when the resource is brought into service. Next, bring the resource into service on the primary node and a full resync will begin.

If using a bitmap (2.6.19 and later kernel or with Red Hat Enterprise Linux 5.4 kernels 2.6.18-164 or later or a supported derivative of Red Hat 5.4 or later):

You must determine which server was the last backup, then take the resource out of service on that server. DataKeeper will then perform a partial resync.

When you exit or disconnect from the GUI applet and then try to reconnect from the same web browser session, the login prompt may not appear.

Workaround: Close the web browser, re-open the browser and then connect to the server. When using the Firefox browser, close all Firefox windows and re-open.

When using DataKeeper in certain environments (e.g., virtualized environments with IDE disk emulation, servers with HP CCISS storage, or solid state devices (SSD), an error may occur when a mirror is created:

This is because LifeKeeper does not recognize the disk in question and cannot get a unique ID to associate with the device.

Workaround: Create a GUID partition and assign a unique ID to the partition. If you cannot create a GUID partition, add a disk pattern to the DEVNAME device_pattern file. For example:

• 
  # cat /opt/LifeKeeper/subsys/scsi/resources/DEVNAME/device_pattern

• 
  /dev/hda*

• 
  /dev/fio*(Fusion IO

• 
  /dev/hio*(

The use of an NU device is not recommended for LifeKeeper 9.2.2 or later. A “mirror out of sync” problem occurs in environments where DataKeeper resources are configured with NU devices.
When upgrading to LifeKeeper 9.2.2 or later, add the following settings to /etc/default/LifeKeeper if NU devices are used:

LKDR_ALLOW_NU=TRUE

How to check whether NU devices are used:
Run the lcdstatus command. If a resource instance ID field contains a character string beginning with NU-, then NU devices are used.