doc
Folders and files
| Name | Name | Last commit date | ||
|---|---|---|---|---|
parent directory.. | ||||
Heartbeat to Corosync/OpenAIS cluster stack conversion ============================================= Please read this description entirely before converting to Corosync/OpenAIS. Every possible precaution was taken to preclude problems. Still, you should run the conversion only when you understood all the steps and the consequences. You need to know your cluster in detail. The conversion program will inform you about changes it makes. It is up to you to verify that the changes are meaningful. Testing the conversion ---------------------- It is possible (and highly recommended) to test the conversion with your heartbeat configuration without making any changes. This way you will get acquainted with the process and make sure that the conversion is done properly. Create a test directory and copy ha.cf, logd.cf, cib.xml, and hostcache to it: $ mkdir /tmp/hb2openais-testdir $ cp /etc/ha.d/ha.cf /tmp/hb2openais-testdir $ cp /var/lib/heartbeat/hostcache /tmp/hb2openais-testdir $ cp /etc/logd.cf /tmp/hb2openais-testdir $ sudo cp /var/lib/heartbeat/crm/cib.xml /tmp/hb2openais-testdir Run the test conversion: $ /usr/lib/heartbeat/hb2openais.sh -T /tmp/hb2openais-testdir or $ /usr/lib/heartbeat/hb2openais.sh -C -T /tmp/hb2openais-testdir to produce corosync.conf. Here is the scripts usage: usage: hb2openais.sh [-UF] [-u user] [-T directory] [revert] -U: skip upgrade the CIB to v1.0 -F: force conversion despite it being done beforehand -u user: a user to sudo with (otherwise, you'd have to run this as root) -C: force conversion to corosync (default is openais) -T directory: a directory containing ha.cf/logd.cf/cib.xml/hostcache (use for testing); with this option files are not copied to other nodes and there are no destructive commands executed; you may run as unprivileged uid Note: You can run the test as many times as you want on the same test directory. Copy files just once. Note: The directory where hb2openais.sh resides may be different, e.g. /usr/lib64/heartbeat. Read and verify the resulting corosync.conf/openais.conf and cib-out.xml: $ cd /tmp/hb2openais-testdir $ less openais.conf $ crm_verify -V -x cib-out.xml The conversion takes several stages: 1. Generate corosync.conf or openais.conf from ha.cf. 2. Rename nodes ids. 3. Upgrade of the CIB to Pacemaker v1.0 (optional) 4. Addition of pingd resource. 5. Conversion of ocfs2 filesystem. 6. Conversion of EVMS2 CSM containers to cLVM2 volumes. 7. Replacement of EVMS2 with clvmd. Conversion from the Heartbeat to the Corosync/OpenAIS cluster stack is implemented in hb2openais.sh which is part of the pacemaker package. Prerequisites ------------- /etc/ha.d/ha.cf must be equal on all nodes. /var/lib/heartbeat/crm/cib.xml must be equal on all nodes. This is enforced by the CRM and users should refrain from making manual changes there. The ocfs2 filesystems must not be mounted. sshd running on all nodes with access allowed for root. The conversion process ---------------------- This procedure is supposed to be run on one node only. Although the main cluster configuration (the CIB) is automatically replicated, there are some files which have to be copied by other means. For that to work, we need sshd running on all nodes and root access working. For some operations root privileges are required. Either run this script as the root user or, if you have a working sudo setup, specify the privileged user (normally root) using the -u option: $ /usr/lib/heartbeat/hb2openais.sh -u root NB: Do not run this procedure on more than one node! 1. Generate corosync.conf or openais.conf from ha.cf. /etc/ha.d/ha.cf is parsed and /etc/ais/openais.conf or /etc/corosync/corosync.conf correspondingly generated. Whereas heartbeat supports several different communication types (broadcast, unicast, multicast), Corosync/OpenAIS uses only multicasting. The conversion tries to create equivalent media, but with some network configurations it may produce wrong results. Pay particular attention to the "interface" sub-directive of the "totem" directive. The openais.conf(5) or corosync.conf(5) man page is the reference documentation. Make sure that your network supports IP multicasts. Corosync/OpenAIS does not support serial communication links. In addition, an Corosync/OpenAIS authentication key is generated if authentication has been used in Heartbeat. Corosync key generation may take some time while corosync-keygen gathers enough entropy for the key. NB: corosync.conf is created with compatibility set to whitetank. 2. Rename nodes ids. Since the nodes UUID are generated by Corosync/OpenAIS in a different manner, the id fields of nodes must be renamed to the node uname. 3. Upgrade of the CIB to Pacemaker v1.0 (optional) There are significant changes introduced in the CIB since heartbeat versions before and including 2.1.4 and the previous pacemaker stable version 0.6. The new CRM in pacemaker still supports the old CIB, but it is recommended to convert to the new version. The hb2openais.sh program performs the upgrade by default. This may be skipped by specifying the -U option. If you don't convert to the new CIB version, the new crm shell and configuration tool will not work. 4. Addition of pingd resource. In heartbeat the pingd daemon could be controlled by the heartbeat itself through the respawn ha.cf directive. Obviously, it is not possible anymore, so a pingd resource has to be created in the CIB. Furthermore, hosts from the "ping" directives (the "ping" nodes) are inserted into the "host_list" pingd resource attribute. 5. Conversion of ocfs2 filesystem. The ocfs2 filesystem is closely related to the cluster stack used. It must be converted if the stack is changed. The conversion script will do this automatically for you. For this step it will start the cluster stack. The conversion is performed by the tunefs.ocfs2 program: tunefs.ocfs2 --update-cluster-stack For more details on ocfs2 conversion refer to the ocfs2 documentation. Skip the following two items in case you don't have EVMS2 CSM containers. 6. Conversion of EVMS2 CSM containers to cLVM2 volumes. All EVMS2 CSM containers found on the system are converted by csm-converter (see README.csm-converter for more details). For volume groups referenced in existing resources the CIB (/dev/evms/<csm-container>/lvm2/<vgname>/<lvname>), new LVM resources are created. Order and collocation constraints are created for those resources and new LVM resources to ensure proper start/stop order and resource placement. 7. Non-LVM EVMS2 Skip this in case you don't have EVMS2 resources. It is not possible to deal with this on a SLE11 system, so you should convert it to a compatibility volume on SLES10, which would turn the it into a LVM2 volume group. The CIB then should be modified accordingly. Enforcing conversion -------------------- There is a simple mechanism which prevents running the conversion process twice in a row. If you know what you are doing, it is possible to force the conversion using the -F option. After the conversion -------------------- Once the conversion has been finished, you may start the new cluster stack: # /etc/init.d/openais start (for SLE11 HAE >=SP1 too) or # /etc/init.d/corosync start Put resources back to the managed mode in case they were previously unmanaged. Backup ------ The conversion procedure also creates backup of all affected files. It is possible to revert to the version from the time of backup: # /usr/lib/heartbeat/hb2openais.sh revert Note that the revert process is executed only on the node on which the conversion took place. NB: hostcache and hb_uuid files (in /var/lib/heartbeat) are not removed. They are not used by Corosync/OpenAIS, hence, once you're content with the conversion, you may safely remove them. Affected files -------------- All file processing is done on the node where conversion runs. The CIB is the only file which is converted: /var/lib/heartbeat/crm/cib.xml The CIB is removed on all other nodes. The following files are generated: /etc/ais/openais.conf /etc/ais/authkey or /etc/corosync/corosync.conf /etc/corosync/authkey The following files are removed on all nodes: /var/lib/heartbeat/crm/cib.xml.sig /var/lib/heartbeat/crm/cib.xml.last /var/lib/heartbeat/crm/cib.xml.sig.last /var/lib/heartbeat/hostcache /var/lib/heartbeat/hb_uuid The Corosync/OpenAIS specific files are copied to all nodes using ssh. The CIB is automatically replicated by the CRM and it is not copied to other nodes. References ---------- http://www.clusterlabs.org/doc/en-US/Pacemaker/1.0/html/Pacemaker_Explained openais.conf(5) corosync.conf(5)