Difference between pages "Install/ru/Partitioning" and "Virtual Packages"

< Install‎ | ru(Difference between pages)
(Подготовка жесткого диска)
 
(two first cases for virtuals)
 
Line 1: Line 1:
<noinclude>
+
Virtual packages are special packages that correspond to a feature that can be satisfied by one or more package(s). This Wiki page aims to describe when and how to use them correctly, and what are their implications.
{{InstallPart|процесс разбиения диска и создания файловых систем}}
+
</noinclude>
+
=== Подготовка жесткого диска ===
+
  
В этой части  мы научимся различным способам установки Funtoo Linux -- и загрузки с -- жесткого диска.
+
== Virtual packages, metapackages and package sets ==
 +
Virtual packages, metapackages and package sets are similar concepts. However, they have a few important differences that make them fit for different use cases.
  
==== Введение ====
+
Virtual packages and metapackages are regular Funtoo packages (ebuilds) that install no files. Instead, they cause other packages to be installed by specifying them in their runtime dependencies. They can both be used in any context valid for regular packages. They can have multiple versions, slots and USE flags. They have to be located in an active repository, and once there they can be installed and uninstalled like regular packages.
  
В прежние времена существовал лишь один способ загрузить PC-совместимый компьютер. Все наши дектопы и сервера имели стандартный PC BIOS, все наши харды использовали MBR и были разбиты используя схему разбивки MBR. Вот как это все было и нам это нравилось!
+
Package sets are not packages but special atoms supported by Portage. Package sets can only specify other packages, either via a static list or dynamically (e.g. via running Python code that determines the package list). Package sets can't be versioned and don't have USE flags. Package sets can be used alongside packages in emerge commands and other package sets but they can't be referenced inside regular packages. Package sets can be installed into user's system, located in repositories or created by user in Portage configuration.
  
Затем появились EFI и UEFI,  встроенные программы нового образца наряду со схемой разбивки GPT, поддерживающая диски размером более 2.2TБ. Неожиданно, нам стали доступны различные способы установки и загрузки Линукс систем . То, что было единым методом, стало чем-то более сложным.
+
Virtual packages represent a commonly used feature that can be provided by multiple different providers. Virtuals provide a convenient way of specifying all possible alternatives without having to update multiple ebuilds.
  
Let's take a moment to review the options available to you for configuring a hard drive to boot Funtoo Linux. This Install Guide uses, and recommends, the old-school method of BIOS booting and using an MBR. It works and (except for rare cases) is universally supported. There's nothing wrong with it. If your system disk is 2TB or smaller in size, it won't prevent you from using all of your disk's capacity, either.
+
Metapackages and package sets are used to represent lists of packages that user may want to install together. They provide a convenience for users, e.g. providing a shortcut to install all packages comprising a desktop environment.
  
But, there are some situations where the old-school method isn't optimal. If you have a system disk >2TB in size, then MBR partitions won't allow you to access all your storage. So that's one reason. Another reason is that there are some so-called "PC" systems out there that don't support BIOS booting anymore, and force you to use UEFI to boot. So, out of compassion for people who fall into this predicament, this Install Guide documents UEFI booting too.
+
== When virtual packages can be used? ==
 +
For virtual package ebuild to work correctly, the two following requirements must be met:
 +
# the virtual providers must be interchangeable at runtime with no consequences to the reverse dependencies. In other words, installing another provider and removing the currently used provider must not cause any breakage or require reverse dependencies to be rebuilt.
 +
# Reverse dependencies need to have consistent, predictable requirements for the alternatives. In other words, the packages must not require a very specific versions of the alternatives.
  
Our recommendation is still to go old-school unless you have reason not to. The boot loader we will be using to load the Linux kernel in this guide is called GRUB, so we call this method the '''BIOS + GRUB (MBR)''' method. It's the traditional method of setting up a PC-compatible system to boot Linux.
+
Virtuals can not be used if the underlying packages don't provide binary compatibility at least between predictable range of versions.
  
If you need to use UEFI to boot, we recommend not using the MBR at all for booting, as some systems support this, but others don't. Instead, we recommend using UEFI to boot GRUB, which in turn will load Linux. We refer to this method as the '''UEFI + GRUB (GPT)''' method.
+
== Common uses for virtual packages ==
 +
=== System components and services ===
 +
Example: ''virtual/service-manager''
  
And yes, there are even more methods, some of which are documented on the [[Boot Methods]] page. We used to recommend a '''BIOS + GRUB (GPT)''' method but it is not consistently supported across a wide variety of hardware.
+
One of the common uses for virtuals is to define abstract ''system services''. Those virtuals are not very specific on how those services are provided. They are mostly intended to be used in the @system package set, to ensure that the user system doesn't lack key components such as a service manager or a package manager.
  
'''The big question is -- which boot method should you use?''' Here's how to tell.
+
The providers for this kind of virtuals do not have to meet any specific requirements except for having a particular function. In particular, there's no requirement for common configuration or provided executables. The user is responsible for ensuring that the installed implementation is set up and working.
  
;Principle 1 - Old School: If you can reliably boot System Rescue CD and it shows you an initial light blue menu, you are booting the CD using the BIOS, and it's likely that you can thus boot Funtoo Linux using the BIOS. So, go old-school and use BIOS booting, ''unless'' you have some reason to use UEFI, such as having a >2.2TB system disk. In that case, see Principle 2, as your system may also support UEFI booting.
+
=== Tools provided by multiple packages ===
 +
Example: ''virtual/eject''
  
;Principle 2 - New School: If you can reliably boot System Rescue CD and it shows you an initial black and white menu -- congratulations, your system is configured to support UEFI booting. This means that you are ready to install Funtoo Linux to boot via UEFI. Your system may still support BIOS booting, but just be trying UEFI first. You can poke around in your BIOS boot configuration and play with this.
+
This kind of virtuals is used when multiple packages may provide tools with the same names. The virtual is used in packages that rely on those tools being present, in particular when the tools are used at build-time of the package or are called by package's scripts (executables).
  
;What's the Big Difference between Old School and New School?: Here's the deal. If you go with old-school MBR partitions, your <code>/boot</code> partition will be an ext2 filesystem, and you'll use <code>fdisk</code> to create your MBR partitions. If you go with new-school GPT partitions and UEFI booting, your <code>/boot</code> partition will be a vfat filesystem, because this is what UEFI is able to read, and you will use <code>gdisk</code> to create your GPT partitions. And you'll install GRUB a bit differently. That's about all it comes down to, in case you were curious.
+
While the tools don't necessarily need to be fully compatible, they need to have a common basic usage. In particular, when a tool from one provider is replaced by a tool from another, the reverse dependencies must remain in working state, with no need for rebuilds or configuration adjustments.
 
+
;Also Note: To install Funtoo Linux to boot via the New School UEFI method, you must boot System Rescue CD using UEFI -- and see an initial black and white screen. Otherwise, UEFI will not be active and you will not be able to set it up!
+
 
+
{{Note|'''Some motherboards may appear to support UEFI, but don't.''' Do your research. For example, the Award BIOS in my Gigabyte GA-990FXA-UD7 rev 1.1 has an option to enable UEFI boot for CD/DVD. '''This is not sufficient for enabling UEFI boot for hard drives and installing Funtoo Linux.''' UEFI must be supported for both removable media (so you can boot System Rescue CD using UEFI) as well as fixed media (so you can boot your new Funtoo Linux installation.) It turns out that later revisions of this board (rev 3.0) have a new BIOS that fully supports UEFI boot.  This may point to a third principle -- know thy hardware.}}
+
 
+
==== Old-School (BIOS/MBR) Method ====
+
 
+
{{Note|Use this method if you are booting using your BIOS, and if your System Rescue CD initial boot menu was light blue. If you're going to use the new-school method, [[#New-School (UEFI/GPT) Method|click here to jump down to UEFI/GPT.]]}}
+
 
+
===== Preparation =====
+
 
+
First, it's a good idea to make sure that you've found the correct hard disk to partition. Try this command and verify that <code>/dev/sda</code> is the disk that you want to partition:
+
 
+
<console>
+
# ##i##fdisk -l /dev/sda
+
 
+
Disk /dev/sda: 640.1 GB, 640135028736 bytes, 1250263728 sectors
+
Units = sectors of 1 * 512 = 512 bytes
+
Sector size (logical/physical): 512 bytes / 512 bytes
+
I/O size (minimum/optimal): 512 bytes / 512 bytes
+
Disk label type: gpt
+
 
+
 
+
#        Start          End    Size  Type            Name
+
1        2048  1250263694  596.2G  Linux filesyste Linux filesystem
+
</console>
+
 
+
Now, it's recommended that you erase any existing MBR or GPT partition tables on the disk, which could confuse the system's BIOS at boot time. We do this using <code>sgdisk</code>:
+
{{fancywarning|This will make any existing partitions inaccessible! You are '''strongly''' cautioned and advised to backup any critical data before proceeding.}}
+
 
+
<console>
+
# ##i##sgdisk --zap-all /dev/sda
+
 
+
Creating new GPT entries.
+
GPT data structures destroyed! You may now partition the disk using fdisk or
+
other utilities.
+
</console>
+
 
+
This output is also nothing to worry about, as the command still succeded:
+
 
+
<console>
+
***************************************************************
+
Found invalid GPT and valid MBR; converting MBR to GPT format
+
in memory.
+
***************************************************************
+
</console>
+
 
+
===== Partitioning =====
+
 
+
Now we will use <code>fdisk</code> to create the MBR partition table and partitions:
+
 
+
<console>
+
# ##i##fdisk /dev/sda
+
</console>
+
 
+
Within <code>fdisk</code>, follow these steps:
+
 
+
'''Empty the partition table''':
+
 
+
<console>
+
Command (m for help): ##i##o ↵
+
</console>
+
 
+
'''Create Partition 1''' (boot):
+
 
+
<console>
+
Command (m for help): ##i##n ↵
+
Partition type (default p): ##i##↵
+
Partition number (1-4, default 1): ##i##↵
+
First sector: ##i##↵
+
Last sector: ##i##+128M ↵
+
</console>
+
 
+
'''Create Partition 2''' (swap):
+
 
+
<console>
+
Command (m for help): ##i##n ↵
+
Partition type (default p): ##i##↵
+
Partition number (2-4, default 2): ##i##↵
+
First sector: ##i##↵
+
Last sector: ##i##+2G ↵
+
Command (m for help): ##i##t ↵
+
Partition number (1,2, default 2): ##i## ↵
+
Hex code (type L to list all codes): ##i##82 ↵
+
</console>
+
 
+
'''Create the root partition:'''
+
 
+
<console>
+
Command (m for help): ##i##n ↵
+
Partition type (default p): ##i##↵
+
Partition number (3,4, default 3): ##i##↵
+
First sector: ##i##↵
+
Last sector: ##i##↵
+
</console>
+
 
+
'''Verify the partition table:'''
+
 
+
<console>
+
Command (m for help): ##i##p
+
 
+
Disk /dev/sda: 298.1 GiB, 320072933376 bytes, 625142448 sectors
+
Units: sectors of 1 * 512 = 512 bytes
+
Sector size (logical/physical): 512 bytes / 512 bytes
+
I/O size (minimum/optimal): 512 bytes / 512 bytes
+
Disklabel type: dos
+
Disk identifier: 0x82abc9a6
+
 
+
Device    Boot    Start      End    Blocks  Id System
+
/dev/sda1          2048    264191    131072  83 Linux
+
/dev/sda2        264192  4458495  2097152  82 Linux swap / Solaris
+
/dev/sda3        4458496 625142447 310341976  83 Linux
+
</console>
+
 
+
'''Write the parition table to disk:'''
+
 
+
<console>
+
Command (m for help): ##i##w
+
</console>
+
 
+
Your new MBR partition table will now be written to your system disk.
+
 
+
{{Note|You're done with partitioning! Now, jump over to [[#Creating filesystems|Creating filesystems]].}}
+
 
+
==== New-School (UEFI/GPT) Method ====
+
 
+
{{Note|Use this method if you are booting using UEFI, and if your System Rescue CD initial boot menu was black and white. If it was light blue, this method will not work.}}
+
 
+
The <tt>gdisk</tt> commands to create a GPT partition table are as follows. Adapt sizes as necessary, although these defaults will work for most users. Start <code>gdisk</code>:
+
 
+
<console>
+
# ##i##gdisk
+
</console>
+
 
+
Within <tt>gdisk</tt>, follow these steps:
+
 
+
'''Create a new empty partition table''' (This ''will'' erase all data on the disk when saved):
+
 
+
<console>
+
Command: ##i##o ↵
+
This option deletes all partitions and creates a new protective MBR.
+
Proceed? (Y/N): ##i##y ↵
+
</console>
+
 
+
'''Create Partition 1''' (boot):
+
 
+
<console>
+
Command: ##i##n ↵
+
Partition Number: ##i##1 ↵
+
First sector: ##i##↵
+
Last sector: ##i##+500M ↵
+
Hex Code: ##i##↵
+
</console>
+
 
+
'''Create Partition 2''' (swap):
+
 
+
<console>
+
Command: ##i##n ↵
+
Partition Number: ##i##2 ↵
+
First sector: ##i##↵
+
Last sector: ##i##+4G ↵
+
Hex Code: ##i##8200 ↵
+
</console>
+
 
+
'''Create Partition 3''' (root):
+
 
+
<console>
+
Command: ##i##n ↵
+
Partition Number: ##i##3 ↵
+
First sector: ##i##↵
+
Last sector: ##i##↵##!i## (for rest of disk)
+
Hex Code: ##i##↵
+
</console>
+
 
+
Along the way, you can type "<tt>p</tt>" and hit Enter to view your current partition table. If you make a mistake, you can type "<tt>d</tt>" to delete an existing partition that you created. When you are satisfied with your partition setup, type "<tt>w</tt>" to write your configuration to disk:
+
 
+
'''Write Partition Table To Disk''':
+
 
+
<console>
+
Command: ##i##w ↵
+
Do you want to proceed? (Y/N): ##i##Y ↵
+
</console>
+
 
+
The partition table will now be written to disk and <tt>gdisk</tt> will close.
+
 
+
Now, your GPT/GUID partitions have been created, and will show up as the following ''block devices'' under Linux:
+
 
+
* <tt>/dev/sda1</tt>, which will be used to hold the <tt>/boot</tt> filesystem,
+
* <tt>/dev/sda2</tt>, which will be used for swap space, and
+
* <tt>/dev/sda3</tt>, which will hold your root filesystem.
+
 
+
==== Creating filesystems ====
+
 
+
{{Note|This section covers both BIOS ''and'' UEFI installs. Don't skip it!}}
+
 
+
Before your newly-created partitions can be used, the block devices need to be initialized with filesystem ''metadata''. This process is known as ''creating a filesystem'' on the block devices. After filesystems are created on the block devices, they can be mounted and used to store files.
+
 
+
Let's keep this simple. Are you using old-school MBR partitions? If so, let's create an ext2 filesystem on /dev/sda1:
+
 
+
<console>
+
# ##i##mkfs.ext2 /dev/sda1
+
</console>
+
 
+
If you're using new-school GPT partitions for UEFI, you'll want to create a vfat filesystem on /dev/sda1, because this is what UEFI is able to read:
+
 
+
<console>
+
# ##i##mkfs.vfat -F 32 /dev/sda1
+
</console>
+
 
+
Now, let's create a swap partition. This partition will be used as disk-based virtual memory for your Funtoo Linux system.
+
 
+
You will not create a filesystem on your swap partition, since it is not used to store files. But it is necessary to initialize it using the <code>mkswap</code> command. Then we'll run the <code>swapon</code> command to make your newly-initialized swap space immediately active within the live CD environment, in case it is needed during the rest of the install process:
+
 
+
<console>
+
# ##i##mkswap /dev/sda2
+
# ##i##swapon /dev/sda2
+
</console>
+
 
+
Now, we need to create a root filesystem. This is where Funtoo Linux will live. We generally recommend ext4 or XFS root filesystems. If you're not sure, choose ext4. Here's how to create a root ext4 filesystem:
+
 
+
<console>
+
# ##i##mkfs.ext4 /dev/sda3
+
</console>
+
 
+
...and here's how to create an XFS root filesystem, if you choose to use XFS:
+
 
+
<console>
+
# ##i##mkfs.xfs /dev/sda3
+
</console>
+
 
+
Your filesystems (and swap) have all now been initialized, so that that can be mounted (attached to your existing directory heirarchy) and used to store files. We are ready to begin installing Funtoo Linux on these brand-new filesystems.
+
 
+
{{fancywarning|1=
+
When deploying an OpenVZ host, please use ext4 exclusively. The Parallels development team tests extensively with ext4, and modern versions of <code>openvz-rhel6-stable</code> are '''not''' compatible with XFS, and you may experience kernel bugs.
+
}}
+
 
+
==== Mounting filesystems ====
+
 
+
Mount the newly-created filesystems as follows, creating <code>/mnt/funtoo</code> as the installation mount point:
+
 
+
<console>
+
# ##i##mkdir /mnt/funtoo
+
# ##i##mount /dev/sda3 /mnt/funtoo
+
# ##i##mkdir /mnt/funtoo/boot
+
# ##i##mount /dev/sda1 /mnt/funtoo/boot
+
</console>
+
 
+
Optionally, if you have a separate filesystem for <code>/home</code> or anything else:
+
 
+
<console>
+
# ##i##mkdir /mnt/funtoo/home
+
# ##i##mount /dev/sda4 /mnt/funtoo/home
+
</console>
+
 
+
If you have <code>/tmp</code> or <code>/var/tmp</code> on a separate filesystem, be sure to change the permissions of the mount point to be globally-writeable after mounting, as follows:
+
 
+
<console>
+
# ##i##chmod 1777 /mnt/funtoo/tmp
+
</console>
+

Revision as of 13:31, February 7, 2015

Virtual packages are special packages that correspond to a feature that can be satisfied by one or more package(s). This Wiki page aims to describe when and how to use them correctly, and what are their implications.

Virtual packages, metapackages and package sets

Virtual packages, metapackages and package sets are similar concepts. However, they have a few important differences that make them fit for different use cases.

Virtual packages and metapackages are regular Funtoo packages (ebuilds) that install no files. Instead, they cause other packages to be installed by specifying them in their runtime dependencies. They can both be used in any context valid for regular packages. They can have multiple versions, slots and USE flags. They have to be located in an active repository, and once there they can be installed and uninstalled like regular packages.

Package sets are not packages but special atoms supported by Portage. Package sets can only specify other packages, either via a static list or dynamically (e.g. via running Python code that determines the package list). Package sets can't be versioned and don't have USE flags. Package sets can be used alongside packages in emerge commands and other package sets but they can't be referenced inside regular packages. Package sets can be installed into user's system, located in repositories or created by user in Portage configuration.

Virtual packages represent a commonly used feature that can be provided by multiple different providers. Virtuals provide a convenient way of specifying all possible alternatives without having to update multiple ebuilds.

Metapackages and package sets are used to represent lists of packages that user may want to install together. They provide a convenience for users, e.g. providing a shortcut to install all packages comprising a desktop environment.

When virtual packages can be used?

For virtual package ebuild to work correctly, the two following requirements must be met:

  1. the virtual providers must be interchangeable at runtime with no consequences to the reverse dependencies. In other words, installing another provider and removing the currently used provider must not cause any breakage or require reverse dependencies to be rebuilt.
  2. Reverse dependencies need to have consistent, predictable requirements for the alternatives. In other words, the packages must not require a very specific versions of the alternatives.

Virtuals can not be used if the underlying packages don't provide binary compatibility at least between predictable range of versions.

Common uses for virtual packages

System components and services

Example: virtual/service-manager

One of the common uses for virtuals is to define abstract system services. Those virtuals are not very specific on how those services are provided. They are mostly intended to be used in the @system package set, to ensure that the user system doesn't lack key components such as a service manager or a package manager.

The providers for this kind of virtuals do not have to meet any specific requirements except for having a particular function. In particular, there's no requirement for common configuration or provided executables. The user is responsible for ensuring that the installed implementation is set up and working.

Tools provided by multiple packages

Example: virtual/eject

This kind of virtuals is used when multiple packages may provide tools with the same names. The virtual is used in packages that rely on those tools being present, in particular when the tools are used at build-time of the package or are called by package's scripts (executables).

While the tools don't necessarily need to be fully compatible, they need to have a common basic usage. In particular, when a tool from one provider is replaced by a tool from another, the reverse dependencies must remain in working state, with no need for rebuilds or configuration adjustments.