Difference between revisions of "Agile testbed"

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(Update example network interfaces config)
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==== Installing the machine ====
 
==== Installing the machine ====
  
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* '''Choose a VM host''' to starting the installation on. Peruse the [[#Hardware index|hardware inventory]] and pick one of the available machines in the <span style="background-color: #ffc; padding: 2px; border: 1px solid #ccc;">yellow</span> section.
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* '''Choose a VM host''' to starting the installation on. Peruse the [[#Hardware|hardware inventory]] and pick one of the available machines.
 
* '''Choose a [[#Storage|storage option]]''' for the machine's disk image.
 
* '''Choose a [[#Storage|storage option]]''' for the machine's disk image.
 
* '''Choose OS, memory and disk space''' as needed.
 
* '''Choose OS, memory and disk space''' as needed.
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==== adding a new user to the testbed ====
 
==== adding a new user to the testbed ====
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 +
Users are known from their ldap entries. All it takes to allow another user on the testbed is adding their name to
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/etc/security/access.conf
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on bleek (at least if logging on to bleek is necessary); Adding a home directory on bleek and copying the ssh key of the user to the appropriate file.
 +
 +
Something along these lines (but this is untested):
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test -d $NEWUSER || cp -r /etc/skel /user/$NEWUSER
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chown -R $NEWUSER:`id -ng $NEWUSER` /user/$NEWUSER
  
 
==== removing a user from the testbed ====
 
==== removing a user from the testbed ====
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== Storage ==
 
== Storage ==
  
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The hypervisors of the testbed all connect to the same shared storage backend (known as The Compellent). Some of the nodes through Fibre Channel, the others who don't have that use iSCSI.
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The hypervisors of the testbed all connect to the same shared storage backend (a Fujitsu DX200 system called KLAAS) over iSCSI.
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The Compellent exports two sizable pools to the testbed (and more can be created if needed). These are formatted as LVM groups and shared through a clustered LVM setup.
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The storage backend exports a number of pools to the testbed. These are formatted as LVM groups and shared through a clustered LVM setup.
  
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In libvirt, these VGs are known as 'pools' under the names <code>vmachines</code> and <code>vmachines2</code>.
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In libvirt, the VG is known as a 'pool' under the name <code>vmachines</code> (location <code>/dev/p4ctb</code>).
  
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The older machine with 2TB of disk storage called 'put' is being decommissioned. Remaining VM images will be migrated away.
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=== Clustered LVM setup ===
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 +
The clustering of nodes is provided by corosync. Here are the contents of the configuration file /etc/corosync/corosync.conf:
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totem {
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version: 2
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cluster_name: p4ctb
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token: 3000
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token_retransmits_before_loss_const: 10
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clear_node_high_bit: yes
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crypto_cipher: aes256
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crypto_hash: sha256
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interface {
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ringnumber: 0
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bindnetaddr: 10.198.0.0
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mcastport: 5405
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ttl: 1
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}
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}
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logging {
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fileline: off
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to_stderr: no
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to_logfile: no
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to_syslog: yes
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syslog_facility: daemon
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debug: off
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timestamp: on
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logger_subsys {
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subsys: QUORUM
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debug: off
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}
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}
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quorum {
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provider: corosync_votequorum
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expected_votes: 2
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}
  
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=== Clustered LVM setup ===
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The crypto settings refer to a file /etc/corosync/authkey which must be present on all systems. There is no predefined definition of the cluster, any node can join and that is why the security token is a good idea. You don't want any unexpected members joining the cluster. The quorum of 2 is, of course, because there are only 3 machines at the moment.
  
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Red Hat's CLVM suite is a heavyweight high-availability system based on CMAN and depends on fencing of failing nodes. I've never been happy with it, especially since we lack a proper out-of-band way to do fencing from one node to another. After a couple of gruesome evenings kicking this around I found a better solution in [http://pixelchaos.net/2009/04/23/openais-an-alternative-to-clvm-with-cman/ openais]. This is based on building a quorum of nodes in order to do locking; the only processes required are corosync and clvmd.
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As long as the cluster is quorate everything should be fine. That means that at any time, one of the machines can be maintained, rebooted, etc. without affecting the availability of the storage on the other nodes.
  
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'''Do not use the service scripts in /etc/init.d/corosync or /etc/init.d/clvmd!'''
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As long as at least one node has the cluster up and running, others should be able to join even if the cluster is not quorate. That means that if only a single node out of three is up, the cluster is no longer quorate and storage queries are blocked. But when another node joins the cluster is again quorate and should unblock.
  
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Currently there are two pools on the Compellent formatted as VGs with clustered setup. When adding more pools in the future don't forget to set the clustered flag there as well.
 
  
 
==== installation ====
 
==== installation ====
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 +
Based on Debian 9.
  
 
Install the required packages:
 
Install the required packages:
  
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  apt-get install openais clvmd
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  apt-get install corosync clvm
  
 
Set up clustered locking in lvm:
 
Set up clustered locking in lvm:
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  sed -i 's/^    locking_type = 1$/    locking_type = 3/' /etc/lvm/lvm.conf
 
  sed -i 's/^    locking_type = 1$/    locking_type = 3/' /etc/lvm/lvm.conf
  
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Configure the cluster in /etc/cluster/cluster.conf. All nodes must share the same identical file. This file is currently maintained by [http://bleek.testbed/git/?p=salt.git;a=summary saltstack].
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Make sure all nodes have the same corosync.conf file and the same authkey. A key can be generated with corosync-keygen.
  
 
==== Running ====
 
==== Running ====
  
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Start corosync:
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Start corosync
  
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  aisexec
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  systemctl start corosync
  
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Start the cluster lvm daemon:
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Test the cluster status with
  
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  clvmd -I openais
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  corosync-quorumtool -s
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dlm_tool -n ls
  
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Test if everything works by running
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Should show all nodes.
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  corosync-quorumtool -s
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and if the cluster is quorate:
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Start the iscsi daemon
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  vgdisplay
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systemctl start iscsid
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systemctl start multipathd
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See if the iscsi paths are visible.
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multipath -ll
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3600000e00d2900000029295000110000 dm-1 FUJITSU,ETERNUS_DXL
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size=2.0T features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='1 alua' wp=rw
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|-+- policy='service-time 0' prio=50 status=active
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| |- 6:0:0:1 sdi 8:128 active ready running
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| `- 3:0:0:1 sdg 8:96  active ready running
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`-+- policy='service-time 0' prio=10 status=enabled
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  |- 4:0:0:1 sdh 8:112 active ready running
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  `- 5:0:0:1 sdf 8:80  active ready running
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3600000e00d2900000029295000100000 dm-0 FUJITSU,ETERNUS_DXL
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size=2.0T features='2 queue_if_no_path retain_attached_hw_handler' hwhandler='1 alua' wp=rw
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|-+- policy='service-time 0' prio=50 status=active
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| |- 4:0:0:0 sdb 8:16  active ready running
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  | `- 5:0:0:0 sdc 8:32  active ready running
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`-+- policy='service-time 0' prio=10 status=enabled
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  |- 3:0:0:0 sdd 8:48  active ready running
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  `- 6:0:0:0 sde 8:64 active ready running
  
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Restarting of the service means killing the corosync and clvmd processes and starting them with the above procedure. The aisexec script actually just starts corosync with an extra environment variable
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Only then start the clustered lvm.
  
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  export COROSYNC_DEFAULT_CONFIG_IFACE="openaisserviceenableexperimental:corosync_parser"
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  systemctl start lvm2-cluster-activation.service
  
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So this could probably be put in /etc/default/corosync as well (future work...)
 
  
 
==== Troubleshooting ====
 
==== Troubleshooting ====
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  ipmi-oem -h host.ipmi.nikhef.nl -u username -p password dell get-system-info service-tag
 
  ipmi-oem -h host.ipmi.nikhef.nl -u username -p password dell get-system-info service-tag
  
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Most machines all run [http://www.debian.org/releases/stable/ Debian squeeze] with [http://www.linux-kvm.org/page/Main_Page KVM] for virtualization, managed by [http://libvirt.org/ libvirt].
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Most machines run [http://www.debian.org/releases/stable/ Debian wheezy] with [http://www.linux-kvm.org/page/Main_Page KVM] for virtualization, managed by [http://libvirt.org/ libvirt].
  
 
See [[NDPF_Node_Functions#P4CTB|the official list]] of machines for the most current view.
 
See [[NDPF_Node_Functions#P4CTB|the official list]] of machines for the most current view.
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   wwid 3600508e000000000d6c6de44c0416105
 
   wwid 3600508e000000000d6c6de44c0416105
 
  }
 
  }
−
 
  
 
== Migration plans to a cloud infrastructure ==
 
== Migration plans to a cloud infrastructure ==

Revision as of 16:59, 6 September 2018

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