1. Platform & Engineering Services CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES AI Images, flavours and partitions Vítor Gouveia, vitor.gouveia@cern.ch IT-PES-PS

2. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES Agenda AI development lifecycle [revisited] AI Images AI flavours AI projects Partitioning 2

3. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES AI development lifecycle [revisited] Complete info: herehere AI configuration components: –Modules Individual, shared and core –ex core modules: base, cernfw, certmgr custom, concat, firewall, etc… –ex shared modules: afs, apache, autofs, bdii, castor, etc… Hieradata of each module is separated from the module and found in hieradata/module_names/ Changes in share and core modules lead to a testing phase before pushing into the master branch –hostgroups manifests Puppet manifests describing the desired configuration of a hostgroup (cluster) Hieradata of each hostgroup is separated from the hostgroup and found in hieradata/hostgroups/ 3

4. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES AI development lifecycle [revisited] Branches –devel entry point for the development cycle –testing the usage of the testing branch is mandatory for changes in core and shared modules Every week, the testing branch is open during a period for pushing the changes and is closed during the tests of the changes. –Master production environment in puppet 4

5. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES AI development lifecycle [revisited] Custom branches –must not be used for production environments –can be used for development and eventually merged into the devel branch Please squash your commits before the merge –Should be used for playing, risk changes, major features, experiments, etc… –should be temporary 5

6. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES AI development lifecycle [revisited] 6

7. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES AI Images and flavours Images –Disk images that work as templates for the virtual machines –All documentation: herehere –nova image-list Currently, IT provides a set of minimal images that are available to be used –There is only one version of the SLC 6 Server 7

8. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES AI Images Custom images –You can create your own images but You need to maintain them –Ex: if you use a image provider from a third party supplier all support should be address to him In any case the Cloud Infrastructure service does not provide any kind of maintenance of the custom images they are private images (i.e. only available in the project you are authenticated for) –The documentation includes the necessary steps to upload your own image The recipe to image creation, conversion and upload is documented A tool is available for this 8

9. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES AI Flavours …define the size of the VM –Number of virtual CPU cores –amount of memory –disk space nova flavor-list a standard set of flavours is already available all documentation herehere 9

10. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES Some notes about the AI Flavours ephemeral parameter –add a secondary disk –exists only during the life time of the VM i.e. when the machine is disappears the ephemeral disk disappear as well –associated with a single VM –persistent across reboots –with ai-bs-vm is mounted as /mnt swap parameter –add a another disk to your VM configured as swap space 10

11. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES Some notes about the AI Flavours Current situation: –we are providing a small set of flavours –...but If you want a specific flavour It is possible to ask –trough the cloud infrastructure support line –should be reasonable flavours (cpu, ram, disk, etc… ) –Ex: Ram <= 16 GB Disk <= 200GB Number of CPUS <= 8 Currently, all the flavours are seen by everyone Future plans: –the possibility to each user create their own private flavours 11

12. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES AI Flavours Current situation if we create a machine with ai-bs- vm with the following flavour /vda -> disk /vdb -> ephemeral /vdc -> swap 12

13. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES AI Projects Projects are groups of related virtual machines such as those concerning a specific activity or production service. –Previously know as tenants Personal Projects –Each user has a personal project associated with a small quota Testing VMs, private VMs, experiences, etc… Shared projects –Provide management of VMs to groups of users for production services Creation of shared project (On Request ) Instructions herehere 13

14. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES AI Projects Currently, the AI Project structure is flat structure. –You cannot have subprojects inside a project Future plans: –Top-level projects managed by a team/service manager with the possibility of delegate subprojects to other team members / users 14

15. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES AI Projects Current shared projects… 15

16. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES Images, Flavours and Projects Support Images, Flavours and Projects support line: https://cern.service-now.com/service- portal/search.do?q=cloud+infrastructure 16

17. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES Partitioning Some notes: –Images created with the tool provided have 10GB (default) –The last partition in the main disk doesn’t grow with the different flavours –The unallocated space can be added to the last partition 17

18. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES Partitioning Recipe If you want to use the extra space of the main disk of the VM This recipe needs manual intervention...to be used with care In the future this will be automated 18 yum –y install cloud-utils growpart reboot pvresize lvextend Resize2fs

19. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES Partitioning We can define two type of partitions: –partitions that need to exist before the boot of the VM “system partitions” (/var, /usr, etc…) –partitions that can be created after the boot of the VM “data partitions” (/usr/vice/cache, /var/lib/mysql, /var/lib/squid, /data) How do we create partitions? –system partitions: The only place available is the kickstart file of the image 19

20. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES Partitioning with Puppet –“Data partitions” Use the ephemeral disk with puppet to create new partitions the puppet module lvm provides the means to create and configure logical volumes, volume groups, etc… –easy to use and configure –provides a starting place to configure your partitions 20

21. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES Partitioning with Puppet Minimal steps to configure new partitions with the lvm module if $ec2_block_device_mapping_ephemeral0 == "/dev/vdb" { #step1: unmont default mount point for the ephemeral disk mount { "/mnt": ensure => absent, } #step2: create the logical volumes (PV/VG are set up automatically) -> lvm::volume { 'mysql': ensure => present, pv => "/dev/vdb", vg => "VolGroup01", fstype => "ext4", size => "120G", } #step3: create the mount points -> file { "/var/lib/mysql": ensure => directory, } -> mount { "/var/lib/mysql": device => "/dev/VolGroup01/mysql", fstype => "ext4", ensure => "mounted", options => "defaults", atboot => true, } -> Class[‘mysql’] make sure this is done before mysql is set up

22. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES AFS cache example Add an AFS cache using the rest of the disk space on the ephemeral disk include afs; #AFS will automatically use all of a /usr/vice/cache partition if present #create partition lvm::volume { ‘afscache': ensure => present, pv => "/dev/vdb", vg => "VolGroup01", fstype => "ext4", require => Lvm::Volume[‘mysql’], #use the remaining space after the mysql partition } #create the mount point -> file { "/usr/vice/cache": ensure => directory, } ->mount { "/usr/vice/cache": device => "/dev/VolGroup01/afscache", fstype => "ext4", ensure => "mounted", options => "defaults", atboot => true, } ->Class[‘afs’] #make sure this is done before AFS is set up

23. CERN IT Department CH-1211 Geneva 23 Switzerland www.cern.ch/i t PES Partitioning support All questions though the configuration management support line: https://cern.service-now.com/service- portal/function.do?name=Configuration- Management 23

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