Description
If there is a problem with a network connection, stop the service that automatically configures the network

In an environment where IP addresses are protected using LifeKeeper, IP resources may conflict with daemons and services that automatically configure the network, such as avahi-daemon. If there is a problem when restoring communication paths or starting IP resources, stop the services that automatically configure the network.

Do not disconnect the network using the ifconfig down or the ip link down command

When a network interface is disconnected using the ifconfig down or ip link down command, a communication path may not be restored after reconnecting, if a virtual IP resource is configured on the interface.

LifeKeeper does not start with systemd target set to multi-user

In order for LifeKeeper to function properly, when running systemctl set-default or systemctl isolate, you must use the lifekeeper-graphical.target (for graphical mode) or lifekeeper-multi-user.target (for console mode). Do not use the normal graphical.target and multi-user.target systemd targets.

DataKeeper Disk UUID Restriction

Starting in version 9.5.0, DataKeeper can no longer mirror disks that do not present a UUID to the operating system. The best way to mirror such a disk is to partition it with a GPT (GUID Partition Table). The “parted” tool can be used for this purpose. Caution: partitioning a disk will destroy any data that is already stored on the disk.

Workaround: See DataKeeper for Linux Troubleshooting
On SLES 15, LifeKeeper logging may not appear in the LifeKeeper log file following a log rotation

If logrotate is run on the command line or if a background log rotation occurs due to the size of the log, LifeKeeper will stop logging.

Workaround: Run systemctl reload rsyslog to resume LifeKeeper logging.

When running lkbackup, an error may appear in the LifeKeeper log

lkbackup[30809: ERROR:lkbackup:::010064:Possible Configuration error: More than one LifeKeeper version is installed on this host

This error message can safely be ignored.

File system labels should not be used in large configurations

The use of file system labels can cause performance problems during boot-up with large clusters. The problems are generally the result of the requirement that to use labels all devices connected to a system must be scanned. For systems connected to a SAN, especially those with LifeKeeper where accessing a device is blocked, this scanning can be very slow.

To avoid this performance problem on Red Hat systems, edit /etc/fstab and replace the labels with the path names.

lkscsid will halt the system when it should issue a sendevent when a disk fails in certain environments

When lkscsid detects a disk failure, it should, by default, issue a sendevent to LifeKeeper to recover from the failure. The sendevent will first try to recover the failure locally and if that fails, will try to recover the failure by switching the hierarchy with the disk to another server. On some versions of Linux (RHEL 5 and SLES11), lkscsid will not be able to issue the sendevent but instead will immediately halt the system. This only affects hierarchies using the SCSI device nodes such as /dev/sda in a shared storage configuration.

DataKeeper Create Resource fails

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


ERROR 104052: Cannot get the hardware ID of the device “/dev/hda3”

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

Workaround: Use a GUID Partition so that LifeKeeper can recognize the disk in question. Otherwise add a pattern for the disk(s) to the DEVNAME device_pattern file, e.g.:


# cat /opt/LifeKeeper/subsys/scsi/resources/DEVNAME/device_pattern
/dev/hda*

Specifying hostnames for API access

The key name used to store LifeKeeper server credentials must match the hostname of the other LifeKeeper server exactly (as displayed by the hostname command on that server). If the hostname is an FQDN, then the credential key must also be the FQDN. If the hostname is a short name, then the key must also be the short name.

Workaround: Make sure that the hostname(s) stored by credstore match the hostname exactly.

Restore of an lkbackup after a resource has been created may leave broken equivalencies

The configuration files for created resources are saved during an lkbackup. If a resource is created for the first time after an lkbackup has been taken, that resource may not be properly accounted for when restoring from this previous backup.

Solution: Restore from lkbackup prior to adding a new resource for the first time. If a new resource has been added after an lkbackup, it should either be deleted prior to performing the restore, or delete an instance of the resource hierarchy, then re-extend the hierarchy after the restore. Note: It is recommended that an lkbackup be run when a resource of a particular type is created for the first time.

Resources removed in the wrong order during failover

In cases where a hierarchy shares a common resource instance with another root hierarchy, resources are sometimes removed in the wrong order during a cascading failover or resource failover.

Solution: Creating a common root will ensure that resource removals in the hierarchy occur from the top down.

  1. Create a gen/app that always succeeds on restore and remove.

  2. Make all current roots children of this new gen/app.



Note: Using /bin/true for the restore and remove script would accomplish this.
RHEL 6.0 is NOT Recommended

SIOS strongly discourages the use of RHEL 6.0. If RHEL 6.0 is used, please understand that an OS update may be required to fix certain issues including, but not limited to:

  • DMMP fails to recover from cable pull with EMC CLARiiON (fixed in RHEL 6.1)

  • md recovery process hangs (fixed in the first update kernel of RHEL 6.1)



Note: In DataKeeper configurations, if the operating system is updated, a reinstall/upgrade of SIOS Protection Suite for Linux is required.
Delete of nested file system hierarchy generates “Object does not exist” message

Solution: This message can be disregarded as it does not create any issues.

filesyshier returns the wrong tag on a nested mount create

When a database has nested file system resources, the file system kit will create the file system for both the parent and the nested child. However, filesyshier returns only the child tag. This causes the application to create a dependency on the child but not the parent.

Solution: When multiple file systems are nested within a single mount point, it may be necessary to manually create the additional dependencies to the parent application tag using dep_create or via the UI Create Dependency.

DataKeeper: Nested file system create will fail with DataKeeper

When creating a DataKeeper mirror for replicating an existing file system, if a file system is nested within this structure, you must unmount it first before creating the File System resource.

Workaround: Manually unmount the nested file systems and remount / create each nested mount.

Changing the mount point of the device protected by Filesystem resource may lead data corruption

The mount point of the device protected by LifeKeeper via the File System resource (filesys) must not be changed. Doing so may lead to the device being mounted on multiple nodes and if a switchover is done and this could lead to data corruption.

XFS file system usage may cause quickCheck to fail.

In the case CHECK_FS_QUOTAS setting is enabled for LifeKeeper installed on Red Hat Enterprise Linux 7 / Oracle Linux 7 / CentOS 7, quickCheck fails if uquota, gquota option is set to the XFS file system resource, which is to be protected.

Solution: Use usrquota, grpquota instead of uquota, gquota for mount options of XFS file system, or, disable CHECK_FS_QUOTAS setting.

Btrfs is not supported

Btrfs (or any other SPS for Linux unsupported filesystem) cannot be used for LifeKeeper files (/opt/LifeKeeper), bitmap files if they are not in /opt/LifeKeeper, lkbackupfiles, or any other LifeKeeper related files. In addition, LifeKeeper does not support protecting Btrfs (or any other SPS for Linux unsupported filesystem) within a resource hierarchy.

Solution: A simple work around for placing /optLifeKeeper on a Btrfs file system is to add a small disk to your instances and format that disk with ext4 or xfs, and mount this filesystem as /opt/LifeKeeper.

  1. Create a small disk to be used for /opt/LifeKeeper
    • A minimum of 110MB is required for software installs
    • Note: In Azure, you can create a 1 GB data disk at a minimum.
    • Note: Additional ARKs and the number of mirrors may increase the total required space.

  2. Once the disk is added to the node and visible, partition the disk (or use lvm).
    • Example: gdisk /dev/sdb
    • Note: How to add a disk to your system is outside the scope of this KBA (contact your sysadmin for your environment)

  3. Format the partition with a supported filesystem (see release notes: http://docs.us.sios.com/spslinux/9.4.1/en/topic/sios-protection-suite-for-linux-release-notes).
    • Example: mkfs.ext4 /dev/sdb1 (where sdb1 was created in step 2)

  4. Add the newly created and formatted partition to /etc/fstab and set it to be automatically mounted on system boot.

  5. Mount the new partition as /opt/LifeKeeper
    • Example: mount /dev/sdb1 /opt/LifeKeeper
    • verify filesystem is mounted

  6. Install SPS-L

  7. After the installation, edit /etc/fstab and add the entry, so the disk can be mounted on reboot.
    • Example: /dev/sdb           /opt/LifeKeeper      ext4


SLES12 SP1 or later on AWS

The following restrictions apply with SLES12 SP1 or later on AWS:

• Cannot set static routing configuration
Automatic IP address configuration via DHCP does not work if a static routing configuration is set in /etc/sysconfig/network/routes. This causes the network not to start correctly.


Solution: Update the routing information in the configuration file by modifying the “ROUTE” parameter in /etc/sysconfig/network/ifroute-ethX


• Hostname is changed even if the “Change Hostname via DHCP” setting is disabled.
The LK service does not work properly if the hostname is rewritten. In SLES12 SP1 or later on AWS, the hostname is changed even after the “Change Hostname via DHCP” setting is disabled.


Solution:



º Update /etc/cloud/cloud.cfg to comment out the “update_hostname” parameter



º Update /etc/cloud/cloud.cfg to set the preserve_hostname parameter to “true”



º Update /etc/sysconfig/network/dhcp to set the DHCLIENT_SET_HOSTNAME parameter to “no”



Shutdown Strategy set to “Switchover Resources” may fail when using Quorum/Witness Kit in Witness mode

Hierarchy switchover during LifeKeeper shutdown may fail to occur when using the Quorum/Witness Kit in Witness mode.

Workaround: Manually switchover resource hierarchies before shutdown.

Edit /etc/services

If the following entry in /etc/service is deleted, LifeKeeper cannot start up.


lcm_server 7365/tcp



Don’t delete this entry when editing the file.

Any storage unit which returns a string including a space for the SCSI ID cannot be protected by LifeKeeper.
Automatic recovery of network may fail when link status goes down on RHEL 6.x systems when using bonded interfaces.

The network doesn’t recover automatically when using bonded interfaces when the link status is lost and then restored on RHEL 6.x. Loss of the link status can occur via a bad network cable, bad switch or hub or a cable reconnection and ifdown -> ifup. To recover from this status, restart the network manually by executing the following command by a user with root authorization.

# service network restart


Please note that this problem is already corrected for RHEL7. Also, this problem doesn’t occur with SLES.

Using bind mounts is not supported


Bind mounts (mount —bind) cannot be used for the file system protected by LifeKeeper.

On SLES running on AWS or Azure, change the network interface configuration file in order to prevent a cloud network plug-in from removing the virtual IP address.

Click here for more details.

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