Quattor Advanced Tutorial, LAL AII v2 Michel Jouvin LAL, Orsay jouvin@lal.in2p3.fr http://grif.fr Quattor Advanced Tutorial, LAL December 18, 2008

Outline Why AII v2 ? How to use it AII Configuration New features Disk partitioning Hooks AII v1 to v2 migration 25/02/201918/12/2008 AII v2

Why AII v2 ? AII v1 had severe limitations AII v2 design principles Based on pan-template templating system, very difficult to maintain Kickstart configuration template File system configuration was very complex and new device type like SW or HW raid were difficult to describe Not modular enough with PXE, DHCP… configuration mixed together AII v2 design principles Direct access to XML profile in the same way as a component (using the same API) Distinction between file systems and block devices A block device can be a JBOD, a HW/SW raid, LVM… A file system uses a block device Based on ncm-lib-blockdevices, also used by ncm-filesystem aii-shellfe is a front-end for various plugins, according to configuration (aii-pxelinux, aii-kernel…) Extensible through hooks 25/02/201918/12/2008 AII v2

How to Use It ? AII is only one command: aii-shellfe --configure node: add DHCP and TFTP configuration for PXE, produce a Kickstart configuration file from node profile --install node: at next PXE boot, start the OS installer --boot node: at next PXE boot, boot from local disk --remove node: remove node from DHCP/TFTP config --rescue node: at next PXE boot, boot a rescue image Require installation of a rescue image A node is typically configured (in the BIOS) to always boot PXE aii-shellfe allows to control what happens at next boot At the end of initial installation, automatically switch from --install to --boot 25/02/201918/12/2008 AII v2

AII Configuration AII configuration in 2 files under /etc/aii aii-shellfe.conf: location where to write Kickstart configuration files and URL where to get XML profiles aii-dhcp.conf: location of DHCP configuration file maintained by Quattor, command to restart DHCPD Config file may be a dedicated file included in main DHCPD config Command to restart DHCPD may synchronize config with a remote node and restart DHCPD on a remote machine Add support for an OS version for PXE Copy a few files from the OS distribution in the same directory as pxelinux.cfg Ensure tftpd is started with the appropriate root directory definition (option –s) 25/02/201918/12/2008 AII v2

Disk Partionning New schema based on a distinct configuration of block devices and file systems Block devices: any combination of HW/SW raid, JBOD, LVM… File systems: how block devices are used New schema is very flexible but also more complex… A generic template to configure file systems and associated block devices: standard/filesystem/config Operations to do a almost always the same… Describe a default layout with all possible block devices and file systems Use variables to enable/disable them, define their size… Default layout is a site-specific template whose name is passed in FILESYSTEM_LAYOUT_CONFIG_SITE See examples for a basis 25/02/201918/12/2008 AII v2

Hooks Allow to add every required action at different point in installation E.g. install machine certificate during machine insall Several hook point: pre, post… A hook is a Perl script that uses the component API See man aii-hooks Hook declaration example: type begrids_hook = { "module" : string "more_stuf": more_field_types }; bind "/system/aii/hooks/post_reboot/0" = begrids_hook; "/system/aii/hooks/post_reboot" = list ( nlist ("module", "begrid", ...) ); 25/02/201918/12/2008 AII v2

AII v1 to v2 Migration v1 and v2 configuration are not compatible Kickstart template is not use anymore On the server… Can be removed (/usr/lib/aii/osinstall) Templates: AII schema has changed with a real schema defined instead of a schema permitting any key/value pair Should be transparent when using AII variables introduced at the end of AII v1 No reason to use direct configuration path anymore Disk partitioning and file systems use a new schema and must be completely rewritten Use new generic template to configure partitioning with variables if possible 25/02/201918/12/2008 AII v2

Useful Links Quattor QWG wiki https://trac.lal.in2p3.fr/LCGQWG Presentation at Bologna’s Quattor Workshop http://indico.cern.ch/getFile.py/access?contribId=18&ses sionId=2&resId=1&materialId=slides&confId=28976 25/02/201918/12/2008 AII v2