| Version 11 (modified by , 16 years ago) (diff) |
|---|
Initial Installation
Table of Contents
This is a quick introduction to AII configuration. AII is Quattor component in charge of producing Kickstart configuration file used for initial installation.
Configuration specific to initial installation is made of 2 parts :
- AII_xxx variables used to configure base environment (keyboard, language...). This works both for v1 and v2.
- Filesystems and block devices definitions : this is specific to AII v2.
AII Variables
All AII options may be customized through variables. For the complete list, look at the man pages aii-pxelinux(8) and aii-ks(8) or the source code standard/aii/quattor/ks/config.tpl and standard/aii/quattor/pxe/config.tpl.
A typical AII configuration is :
# AII specific parameters variable AII_OSINSTALL_SRV ?= "quattorsrv.lal.in2p3.fr"; # variable AII_ACKSRV ?= "quattorsrv.lal.in2p3.fr"; variable AII_OSINSTALL_ROOT = '/packages/os';
Site-Specific Installation Actions
AII allows to define in a flexible way site-specific actions that must be done at various points in Kickstart. This is done through several hooks.
File Systems and Block Devices
In AII v2, block devices and file systems are declared separatly. Sections belows give some details about how to configure each of them. Block devices entries are used only if referenced by a file system or another block device entry.
Generic Configuration of Filesystems
QWG Templates provide a generic template to configure file systems on a typical system with 1 or 2 disks. It is based on template sites/example/site/filesystems/layout.tpl that may be customized according to your site needs with a limited set of variables. In addition to this generic template to define disk layouts, QWG templates provides 2 examples of how to use it :
- sites/example/site/filesystems/glite.tpl : define a default system disk layout for a typical grid system running gLite. This template also provides some variables to further refine this default layout without redefining everything.
- sites/example/site/filesystems/ce_nfs_server.tpl : add to the basic layout provided by the previous template 2 filesystems, one for home directories and one for VO software areas. It is intended to be used on a machine configured as a NFS server to serve these file systems to WNs (and possibly the CE if it is not the NFS server).
These two templates are just provided as examples on how to use sites/example/site/filesystems/layout.tpl. But this template can be used to build many other layouts. The basic idea is to declare in this template all the possible file system that can be found on a system, most of them with zero size meaning they will not be created unless the variable used to define their size is explicitly set to a non-zero value.
To use these templates, you need to define the following 2 variables in your node profile or one of your site-specific templates (typically pro_site_cluster_info) :
FILESYSTEM_CONFIG_SITE: define this variable to be source:templates/trunk/sites/example/site/filesystems/layout.tpl sites/example/site/filesystems/layout.tpl]. This is the default in gLite templates.FILESYSTEM_LAYOUT_CONFIG_SITE: define this variable to the name of a template that customize source:templates/trunk/sites/example/site/filesystems/layout.tpl sites/example/site/filesystems/layout.tpl] by defining the appropriate variables. gLite templates define it to be sites/example/site/filesystems/glite.tpl by default.
File Systems
Filesystems are declared as an ordered list allowing to customize different aspect of a file system (mount point, mount options, format, ...). Each file system in the list is described as a nlist. One property in the nlist describing a file system is block device : its value is an entry in the structure describing block devices (physical disk, logical volumes, ...). To add or modify a filesystem on a system, it is recommended to use 'fileystem_mod` function. An example is :
"/system/filesystems" = filesystem_mod(
list(nlist ("block_device", "partitions/" + DISK_PART_BOOT,
"mountpoint", "/boot",
"format", true,
"mount", true,
"preserve", false,
"type","ext2"),
nlist ("block_device", "partitions/" + DISK_PART_SWAP,
"format", true,
"mount", true,
"preserve", false,
"type","swap",
"mountpoint","swap"),
nlist ("block_device", "partitions/" + DISK_PART_ROOT,
"format", true,
"preserve", false,
"mount", true,
"type","ext3",
"mountpoint","/"),
nlist ("block_device", "logical_volumes/usrvol",
"format", true,
"preserve", false,
"mount", true,
"type","ext3",
"mountpoint","/usr"),
);
Look at sites/example/site/filesystems/layout.tpl for more details.
Block Devices
Block devices define logical and physical devices used by file systems. They can be logical devices, HW or SW raid devices, physical disks... A block device can be made of other block devices, for example a logical device is made of one or more physical devices.
Unlike file systems which are described with an ordered list, block devices are defined as a nlist. At installation time, they are processed (partition creation, logical volume creation...) in the order of file systems who use them.
Several functions are available to help in declaration of block devices, in particular :
partition_add(PHYS_DISK,partition_nlist): allow to add entries efficiently in/system/blockdevices/partitionsnlist.lvm_add(VOL_GROUP,logvol_nlist): allow to add entries efficiently in/system/blockdevices/logical_volumesnlist.
An example of block device definition is :
"/system/blockdevices/physical_devs" = npush (
DISK_BOOT_DEV, nlist ("label", "msdos")
);
"/system/blockdevices/partitions" = partitions_add (DISK_BOOT_DEV, nlist (DISK_PART_BOOT, 64*MB,
DISK_PART_SWAP, 4*GB,
DISK_PART_ROOT, 1*GB,
DISK_PART_LOGPARTS, -1
)
);
"/system/blockdevices/volume_groups" = npush (
"vg0", nlist ("device_list", list ("partitions/" + DISK_PART_LOGPARTS))
);
"/system/blockdevices/logical_volumes" = lvs_add ("vg0", nlist("usrvol", 5*GB,
"homevol", 512*MB,
"tmpvol", 1*GB,
"varvol", -1,
)
);
Look at sites/example/site/filesystems/layout.tpl for more details.
AII v1 to v2 Migration
When migrating from AII v1 to v2, the AII configuration itself should not require many changes, as long as you are using AII-related variables, except for the declaration of Kickstart actions which replace former Kickstart template. The aii-update(8) man page provides complete information on what is needed now.
On the other hand, file system definition is not backward compatible and must be edited as described before. The full description of the data structures and helper functions is available at CERN wiki You can also find some useful hints and additions at https://twiki.cern.ch/twiki/bin/view/ELFms/QuattorUpdateFSLayout.
