Linked by Thom Holwerda on Thu 3rd Aug 2006 16:49 UTC, submitted by IdaAshley
Linux "The Linux initial RAM disk is a temporary root file system that is mounted during system boot to support the two-state boot process. The initrd contains various executables and drivers that permit the real root file system to be mounted, after which the initrd RAM disk is unmounted and its memory freed. In many embedded Linux systems, the initrd is the final root file system. This article explores the initial RAM disk for Linux 2.6, including its creation and use in the Linux kernel."
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Antiquitie
by Sphinx (2.84) on Thu 3rd Aug 2006 19:17 UTC
Sphinx
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2005-07-09
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Read up on the initial ram file system that's been in the kernel since 2.5 instead, initrd will probably be deprecated at some point.

RE: Antiquitie
by Don T. Bothers (4.52) on Thu 3rd Aug 2006 19:37 UTC in reply to "Antiquitie"
Don T. Bothers Member since:
2006-03-15
Fans: 1

If by "deprecated at some point" you mean deprecated after 10 years, then you are right. But for everyone else who is interested in getting into Linux between now and 2015, I would suggest that they read up and discover more about initrd. The simple fact is that all major distributions and most minor distributions use initrd to boot up. If you are going to be doing anything with Linux, you should know at least a little bit about it. Most of those millions of installations out there will not be replaced anytime soon and I doubt anyone will bother with "fixing" something that in essence runs once at bootup and then gets completely out of the way. How many people actually botheed to replace LILO with Grub on a perfectly working machine?

RE[2]: Antiquitie
by bogolisk (1) on Thu 3rd Aug 2006 20:04 UTC in reply to "RE: Antiquitie"
bogolisk Member since:
2006-08-03
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Don T. Bothers
I would suggest that they read up and discover more about initrd. The simple fact is that all major distributions and most minor distributions use initrd to boot up.

(Almost) Everyone has already moved on! Dapper's initrd is actually an initramfs (gzipped cpio archive.) Apparently FC5 did the samething. The embedded guys on 2.6 already switched to in-kernel-initramfs. The article should have been written 3 years ago.

Don T. Bothers:
How many people actually botheed to replace LILO with Grub on a perfectly working machine?

Well, AFAIK, lilo loads initramfs just fine. It doesn't care that the blob is a file-system image (initrd) or a gzipped cpio archive (initramfs). It's a binary blob.

Edited 2006-08-03 20:05

RE[3]: Antiquitie
by superman (3.88) on Thu 3rd Aug 2006 21:27 UTC in reply to "RE[2]: Antiquitie"
superman Member since:
2006-08-01
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> (Almost) Everyone has already moved on! Dapper's initrd is actually an initramfs (gzipped cpio archive.)

initramfs is initrd !!!

> Apparently FC5 did the samething.

Fedora switch to gzipped cpio archive file system around FC2.
Red Hat use initrd (but with ext2 file system and not the "new" gzipped cpio image) since RH7.2 !!!

> The article should have been written 3 years ago.

This article is good for you now.

> a file-system image (initrd) or a gzipped cpio archive (initramfs).

initrd and "gzipped cpio archive (initramfs)" is the same thing. initrd is in userlang, initramfs is the inkernel facility to support initrd.

RE[4]: Antiquitie
by tyler (1.2) on Thu 3rd Aug 2006 21:54 UTC in reply to "RE[3]: Antiquitie"
tyler Member since:
2006-08-03
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Common usage has "an initrd" being a filesystem blob and "an initramfs" being the cpio archive.

(Hence the creation utilies named mkinitrd, mkinitramfs.)

The "Manually building a custom initial RAM disk" obviously shows how to make an initrd, while the first section demonstrates unarchiving an initramfs file.

RE[4]: Antiquitie
by bogolisk (1) on Fri 4th Aug 2006 03:55 UTC in reply to "RE[3]: Antiquitie"
bogolisk Member since:
2006-08-03
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from superman
initramfs is initrd !!!

You're so clueless, aren't you. initramfs was designed to be included in the vmlinux image. the piece of code which detects that the initrd is actually an gzipped cpio archive and not a filesystem is just convennient hack so that it can be loaded by the bootloader. It's an entire different piece of code in the kernel. look in the usr subdir in the kernel tree. that's where the standard initramfs is built.
from superman
initrd and "gzipped cpio archive (initramfs)" is the same thing.

Yeah the same thing!!! except that you can have initramfs without initrd. Or you can have initrd without initramfs. Yeah, they're the same thing!!!

Edited 2006-08-04 04:04

RE[2]: Antiquitie
by tyler (1.2) on Thu 3rd Aug 2006 20:05 UTC in reply to "RE: Antiquitie"
tyler Member since:
2006-08-03
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Actually, most distributions now use initramfs instead of initrd.

This is yet another reason why linux isnt
by neozeed (1.52) on Thu 3rd Aug 2006 22:42 UTC
neozeed
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2006-03-03
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ready for anything mainstream. Just ask anyone with a new fangled motherboard that cant 'inject' drivers into the install. Sorry the init ram disk disaster from redhat much like modules is a mistake. Honestly having a computer with gigabytes of ram, a 5mb kernel won't kill anyone. And if you are crying about wasting ram, dont let me catch you running X11!

initrd vs initramfs
by howard (2.84) on Fri 4th Aug 2006 05:02 UTC
howard
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2006-01-08
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http://www.linuxdevices.com/articles/AT4017834659.html

Initrd is a block device in RAM. That block device usually contains a filesystem. Fixed size. You need filesystem drivers that might not be used later.

Initramfs is a filesystem in RAM. No block device. Size adjusts as needed.