Testbed Update Plan

Planning the update of the middleware/development test bed

There is a number of tasks involved in bringing the testbed to where we like to be. We also need to agree on a timeframe in which we like to see these things accomplished.

inventory of current services

This section should list the current services we run and use on the testbeds. For each service, we should explain what we should like to do with it (keep, drop, change?).

Service	System	keep/move/lose	Comments
LDAP	span	lose	to be discontinued after migration to central LDAP
DHCP	span	move	by dnsmasq, /etc/hosts and /etc/ethers. Should migrate elsewhere
DHCP	bleek	keep	bleek is going to be the main home directory and DHCP server, after it's been upgraded.
Cruisecontrol	bleek	move	build system for VL-e and BiG Grid; may move to Hudson. Currently transferred to cruisecontrol.testbed
Hudson	kudde	move	continuous integration, currently for jGridstart but could serve others
Home directories	everywhere	move	should be merged onto single NFS server
X509 host keys and pre-generated SSH keys	span	move	all in /var/local/hostkeys
Robot certificate (etoken)	kudde	keep/move	hardware token is plugged into kudde to generate vlemed robot certificates using cronjob + software in /root/etoken. Token can be moved to another machine but it should remain within the P4CTB
VMWare Server 1.0	bleek	move	If bleek is destined to be home directory server, VMWare should be put on other hardware.

Data plan for precious data

Precious means anything that took effort to put together, but nothing that lives in version control elsewhere. Think home directories, system configurations, pre-generated ssh host keys, X509 host certs, etc.

One idea is to put all of this on a box that is not involved in regular experimentation and messing about, and have backup arranged from this box to Sara with ADSM (which is the current service running on bleek). After this is arranged we begin to migrate precious data from all the other machines here, leaving the boxen in a state that we don't get sweaty palms over scratching and reinstalling them.

Hardware inventory

Perhaps this should be done first. Knowing what hardware we have is prerequisite to making sensible choices about what we try to run where.

Changes here should probably also go to NDPF System Functions.

name	ipmi name*	type	chipset	#cores	mem	OS	disk	service tag	remarks
bleek	bleek	PE1950	Intel 5150 @2.66GHz	4	8GB	CentOS4-64	software raid1 2×500GB disks	CQ9NK2J	High Availability, dual power supply; precious data; backed up
toom.testbed	toom	PE1950	Intel E5440 @2.83GHz	8	16GB	CentOS5-64	Hardware raid1 2×715GB disks	DC8QG3J	current Xen 3 hypervisor with mktestbed scripts
kudde	kudde	PE1950	Intel E5440 @2.83GHz	8	16GB	CentOS5-64	Hardware raid1 2×715GB disks	CC8QG3J	Contains hardware token/robot proxy for vlemed; current Xen 3 hypervisor with mktestbed scripts
span	span	PE2950	Intel E5440 @2.83GHz	8	24GB	CentOS5-64	Hardware raid10 on 4×470GB disks (950GB net)	FP1BL3J	DHCP,DNS,NFS,LDAP; home dirs must be moved to bleek; current Xen 3 hypervisor with mktestbed scripts
melkbus	hals	PEM600	Intel E5450 @3.00GHz	8	32GB	CentOS5-64	2x 320GB SAS disks	76T974J	to be renamed to hals; Oscar's private machine?
put.testbed	put	PE2950						HMXP93J	former garitxako;FreeNAS
blade14.testbed	bl0-14	PEM610	Intel E5504 @2.00GHz	2x4	16GB	OVMS 3.0.3		4NZWF4J	former autana
blade13.testbed	bl0-13	PEM610						5NZWF4J	former arauca; OVM 3.0.3
voor	arrone	PE1950						982MY2J	former arrone; status unclear; Jan Just?
wiers	aulnes	PE1950						B82MY2J	former aulnes; status unknown
ent	(no ipmi)	Mac Mini	Intel Core Duo @1.66GHz	2	2GB	OS X 10.6	SATA 80GB		OS X box (no virtualisation)

• *ipmi name is used for IPMI access; use <name>.ipmi.nikhef.nl.
• System details such as serial numbers can be retrieved from the command line with dmidecode -t 1.
• The service-tags can be retrieved through IPMI, but unless you want to send raw commands with ipmitool first you need freeipmi-tools. This contains ipmi-oem that can be called thus:

ipmi-oem -h host.ipmi.nikhef.nl -u username -p password dell get-system-info service-tag

IPMI serial-over-LAN

• For details, see Serial Consoles. The setup for Debian squeeze is slightly different.
• can be done by ipmitool -I lanplus -H name.ipmi.nikhef.nl -U user sol activate.
• SOL access needs to be activated in the BIOS once, by setting console redirection through COM2.

For older systems that do not have a web interface for IPMI, the command-line version can be used. Install the OpenIPMI service so root can use ipmitool. Here is a sample of commands to add a user and give SOL access.

ipmitool user enable 5
ipmitool user set name 5 ctb
ipmitool user set password 5 '<blah>'
ipmitool channel setaccess 1 5 ipmi=on
# make the user administrator (4) on channel 1.
ipmitool user priv 5 4 1
ipmitool channel setaccess 1 5 callin=on ipmi=on link=on
ipmitool sol payload enable 1 5

Serial over LAN for hardware running Debian squeeze

On Debian squeeze you need to tell grub2 what to do with the kernel command line in the file /etc/default/grub. Add or uncomment the following settings:

GRUB_CMDLINE_LINUX_DEFAULT=""
GRUB_CMDLINE_LINUX="console=tty0 console=ttyS1,115200n8"
GRUB_TERMINAL=console
GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=1 --word=8 --parity=no --stop=1"

Then run update-grub.

Data Migration

Function of machines in the testbed

Bleek.nikhef.nl is designated to become the home directory server, DHCP server and OpenNebula server. It will be the only persistent machine in the entire testbed, the rest should be considered volatile. It will be the only machine where backups are done. But before all this can be arranged, it needs to be reinstalled with CentOS 5 (currently CentOS 4). All important data and configurations are going to be migrated to span.nikhef.nl as an intermediate step, and after the upgrade this will be moved back and merged on bleek.

Disk space usage on bleek (in kB):

50760      etc
317336     lib
432640     opt
877020     export
1035964    root
2353720    var
3258076    usr
357844380  srv

There is a script in place on span.nikhef.nl to do the backup from bleek, where /etc/rsyncd.conf is already set up.

rsync -a --password-file /etc/rsync-bleek-password  --exclude /sys** --exclude /proc** --delete --delete-excluded bleek::export-perm  /srv/backup/bleek/

It's not run automatically, so it should be run manually at the very latest right before reinstalling bleek.

Cruisecontrol migration

The former cruisecontrol instance on bleek has been stopped. The service has ben transferred to cruisecontrol.testbed(toom.nikhef.nl), while the data in /srv/project/rpmbuild has been transferred to span.nikhef.nl and is exported from there with NFS.

Network plan

There are three VLANs in use. All the physical machines (i.e. the hypervisors, Dom0 in Xen terminology) should configure bridges for all three; virtual machines then get interfaces for any combination depending on their role.

vlan	description	network	gateway	ACL
2	P4CTB	194.171.96.16/28	194.171.96.30	No inbound traffic on privileged ports
8	Open/Experimental	194.171.96.32/27	194.171.96.62	Open
untagged	local	10.198.0.0/16		testbed only

Since there is limited public IP available, we should put machines in the local network as much as possible. For outbound connectivity NATting is arranged via their Dom0.

The machines that run Xen 3.0 on CentOS 5 use the following configuration for networking:

/etc/sysconfig/network:

NETWORKING=yes
NETWORKING_IPV6=yes
HOSTNAME=span
FORWARD_IPV4=yes
NOZEROCONF=true
GATEWAY=194.171.96.30
GATEWAYDEV=eth0.2

/etc/sysconfig/network-scripts/ifcfg-eth0:

TYPE=Ethernet
DEVICE=eth0
HWADDR=00:1e:4f:xx:xx:xx
BOOTPROTO=none
ONBOOT=yes
USERCTL=no
IPV6INIT=no
IPV4INIT=yes
NETMASK=255.255.0.0
IPADDR=10.198.x.y

(Fill in the mac address of the actual hardware, and the 10.198.0.0 network config for the machine.)

/etc/sysconfig/network-scripts/ifcfg-eth0.2:

VLAN=yes
DEVICE=eth0.2
BOOTPROTO=static
ONBOOT=yes
TYPE=Ethernet
NETMASK=255.255.255.240
IPADDR=194.171.96.x
USERCTL=no
IPV6INIT=no
IPV4INIT=yes

This should result in a working network configuration before the start of the Xen daemon.

The Xen network scripts to use require an additional script to configure a VLAN bridge without any virtual network devices on it. The file /etc/xen/xend-config.sxp should have:

(network-script 'network-multi-vlan')
(vif-script vif-bridge bridge=xenbr2)

And the script /etc/xen/scripts/network-multi-vlan contains: dir=$(dirname "$0")

"$dir/network-bridge" "$@" vifnum=0
"$dir/network-bridge" "$@" vifnum=2 netdev=eth0.2
"$dir/network-bridge-vlan" "$@" vlan=8 netdev=peth0

The network-bridge-vlan is non-standard; it creates a vlan interface, binds it to a bridge but leaves it unconfigured otherwise. This way the Dom0 doesn't have a Open/Experimental interface itself, but DomUs can connect their vifs to the bridge. The xen scripts are fairly complicated in the way they rename interfaces and transfer addresses and routes to the virtual counterparts; in case things go wrong, diagnostic information may be obtained from:

brctl show
cat /proc/net/vlan/*
ip link show
netstat -rn

but be awary that the Xen scripts actually rename interfaces to make them look like normal ones.

All systems have at least 1GB interface, but put has two which may be trunked. This could be useful for serving machine images. The blade systems have extra interfaces and may be capable of doing iSCSI offloading to the NIC.

TODO: draw a network lay-out.

LDAP migration

We're going to ditch our own directory service (it served us well, may it rest in peace) in favour of the central Nikhef service. This means changing user ids in some (all?) cases which should be done preferable in a single swell foop.

We should request to add a testbed 'service' to LDAP with ourselves as managers, so we can automatically populate /root/.ssh/authorized_keys.

Here's a simple example of an ldapsearch call to find a certain user.

ldapsearch -x -H ldaps://hooimijt.nikhef.nl/ -b dc=farmnet,dc=nikhef,dc=nl uid=dennisvd

And here is the ldap.conf file to use for ldap authentication.

base dc=farmnet,dc=nikhef,dc=nl
timelimit 120
bind_timelimit 120
idle_timelimit 3600
nss_initgroups_ignoreusers root,ldap,named,avahi,haldaemon,dbus,radvd,tomcat,radiusd,news,mailman
uri ldaps://gierput.nikhef.nl/ ldaps://hooimijt.nikhef.nl/ ldaps://stalkaars-01.farm.nikhef.nl/ ldaps://stalkaars-03.farm.nikhef.nl/ ldaps://vlaai.nikhef.nl/
ssl on
tls_cacertdir /etc/openldap/cacerts

Migration to a cloud infrastructure

Previous testbed cloud experiences are reported here.

Currently, using plain libvirt seems to fit most of our needs.

The machines blade13 and blade14 are setup with Debian squeeze, libvirt and KVM with a Fiber Channel link to the compellent storage over which clustered LVM is defined to share access to the pool.

The machines arrone and aulnes are setup with Debian squeeze, libvirt and KVM with an NFS storage backend on put.testbed (storage.testbed) over which clustered LVM is defined to share access.

It happens that on reboot of a machine you need to manually start the pool and/or run vgscan. It is unclear at this moment why this would happen.

virsh pool-start vmachines

 error: Failed to start pool vmachines
 error: internal error '/sbin/vgchange -ay vmachines' exited with non-zero status 5 and signal 0:   Error locking on node arrone.testbed: Volume group for uuid not found: hI7udF9MvGpKkvkympcNG42glpwtwDeqhv7xV9wKHHdv9tDxQ9j8Lhgqem1esMcA

The following sequence of commands can be useful:

vgscan

 Reading all physical volumes.  This may take a while...
 Found volume group "vmachines" using metadata type lvm2

virsh pool-start vmachines

 Pool vmachines started

virsh pool-list --all

 Name                 State      Autostart 
 -----------------------------------------
 default              active     yes       
 put.testbed          active     yes       
 vmachines            active     yes

Also check the state of the LVM cluster, logs are in /var/log/cluster/. In the (rare) case the fence daemon has blocked the use of the cluster, the other machine in the cluster must be told it is ok to release the block. What the other machine is can be found in /etc/cluster/cluster.conf.

fence_ack_manual other-machine

Installing clustered lvm for live migration

The machines arrone.testbed and aulnes.testbed, running Debian stable, are now equipped with a clustered LVM setup with an iSCSI device as the backend storage. The iSCSI device is served by put.testbed running FreeNAS.

Documentation to set up CLVM is available for Red Hat and Debian, both should be comparable.

First, a cluster needs to be defined and all systems in the cluster need to use the same definition. Put the file in /etc/cluster/cluster.conf:

<cluster name="vmachines" config_version="1">
  <cman expected_votes="1" two_node="1">
  </cman>
  <clusternodes>
    <clusternode name="arrone.testbed" votes="1" nodeid="1">
      <fence>
      </fence>
    </clusternode>
    <clusternode name="aulnes.testbed" votes="1" nodeid="2">
      <fence>
      </fence>
    </clusternode> 
  </clusternodes>
  <logging to_syslog="yes" to_logfile="yes" syslog_facility="daemon" syslog_priority="info">
  </logging>
  <fence_daemon post_join_delay="30" />
  <totem rrp_mode="none" secauth="off"/>
</cluster>

The setting 'two_node' is a special case for two node clusters, because there is no sensible way to do majority voting. In case one of the machines fails, the other will block to fence the first machine (which is a manual operation in our case) but the cluster can carry on with just one machine if needs be.

The machines keep an eye on one another through multicast, and therefore it is important to remove the following line from /etc/hosts:

127.0.1.1 arrone.testbed

which the Debian installation inserted. This makes the cluster manager daemon bind the wrong device for multicasts (the loopback device).

Another snag found on installation is the missing directory /var/run/lvm, which causes the startup script of clvm to fail. Once this is fixed, run

/etc/init.d/cman start
/etc/init.d/clvm start

Finally, the file

/etc/lvm/lvm.conf

needs to be edited to set

locking_type = 3

in order to use clustered locking.

Through this shared storage it is possible to do live migration of virtual machines between arrone and aulnes.

Installing Debian on blade 13 and 14 with Fiber Channel

This is a quick note to record a recent quirk. Although FC support on Debian works fine, using the multipath-tools-boot package is a bit tricky. It will update the initrd to include the multipath libraries and tools, to make it available at boot time.

This happened on blade-13; on reboot it was unable to mount the root partition (The message was 'device or resource busy') because the device mapper had somehow taken hold of the SCSI disk. By changing the root=UUID=xxxx stanza in the GRUB menu to root=/dev/dm-2 (this was guess-work) I managed to boot the system. There were probably several remedies to resolve the issue:

1. rerun update-grub. This should replace the UUID= with a link to /dev/mapper/xxxx-part1
2. blacklist the disk in the device mapper (and running mkinitramfs)
3. remove the multipath-tools-boot package altogether.

I opted for blacklisting; this is what's in /etc/multipath.conf:

blacklist {
 wwid 3600508e000000000d6c6de44c0416105
}

A bonnie test of a VM with disk on local disk vs. a VM with disk on FC:

• lofarwn.testbed had its disk locally

Version 1.03e       ------Sequential Output------ --Sequential Input- --Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
lofarwn          4G 20869  35 30172   5 23198   6 45957  85 510971  84 +++++ +++
                    ------Sequential Create------ --------Random Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16 16759  99 +++++ +++ +++++ +++ 16810 100 +++++ +++ +++++ +++
lofarwn,4G,20869,35,30172,5,23198,6,45957,85,510971,84,+++++,+++,16,16759,99,+++++,+++,+++++,+++,16810,100,+++++,+++,+++++,+++

• ige-cert.testbed has disk on LVM via FC.

Version 1.03e       ------Sequential Output------ --Sequential Input- --Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
ige-cert         4G 53384  96 216611  37 102283  24 51060  95 689474  79 +++++ +++
                    ------Sequential Create------ --------Random Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16 12676 100 +++++ +++ +++++ +++ 12761  99 +++++ +++ +++++ +++
ige-cert,4G,53384,96,216611,37,102283,24,51060,95,689474,79,+++++,+++,16,12676,100,+++++,+++,+++++,+++,12761,99,+++++,+++,+++++,+++