Fedora Linux Support Community & Resources Center
  #1  
Old 16th July 2012, 06:52 PM
merilius Offline
Registered User
 
Join Date: Jan 2009
Posts: 27
linuxfirefox
[SOLVED] ext3 -> ext4 conversion of "/" and old Grub

Hi,

I am running F17 with / and /boot mounted as ext3. I want to convert / to ext4 to gain some performance, but I still have GRUB in my MBR installed from the F15 times (and GRUB2 package installed but unused). I had bad experience with GRUB2 and don't want to switch to GRUB2 yet.

Will GRUB be able to boot my system after the conversion? (I am going to convert the filesystem offline of course from some boot media)
At
https://ext4.wiki.kernel.org/index.p...system_to_ext4
they say
Quote:
If you convert your root filesystem ("/") to ext4, and you use the GRUB boot loader, you will need to install a version of GRUB which understands ext4. Your system may boot OK the first time, but when your kernel is upgraded, it will become unbootable (press Alt+F+F to check the filesystem).
But I don't have GRUB installed. Will it work or am I asking for trouble?

Met

Last edited by merilius; 19th July 2012 at 12:24 PM. Reason: solved now
Reply With Quote
  #2  
Old 16th July 2012, 07:14 PM
Yellowman
Guest
 
Posts: n/a
linuxfirefox
Re: ext3 -> ext4 conversion of "/" and old Grub

As far as I remember F15 grub is EXT4 aware.

Don't forget to change the fstab / mount type to ext4 and redo initramfs afterwards
Code:
su
mv /boot/initramfs-$(uname -r).img /boot/initramfs-$(uname -r)-backup.img
dracut /boot/initramfs-$(uname -r).img $(uname -r)

Last edited by Yellowman; 16th July 2012 at 07:19 PM.
Reply With Quote
  #3  
Old 16th July 2012, 08:18 PM
jpollard Offline
Registered User
 
Join Date: Aug 2009
Location: Waldorf, Maryland
Posts: 6,870
linuxfirefox
Re: ext3 -> ext4 conversion of "/" and old Grub

You won't really gain any performance.

The performance improvement comes from files containing extents. So until such files are created, there won't be any performance improvements...

Also note, once extents ARE used, you can't go back to ext3.
Reply With Quote
  #4  
Old 16th July 2012, 08:45 PM
merilius Offline
Registered User
 
Join Date: Jan 2009
Posts: 27
linuxfirefox
Re: ext3 -> ext4 conversion of "/" and old Grub

@Yellowman: Thanks. Are ext4/3/2 drivers compiled into the kernel statically in Fedora? lsmod does not show any such modules in use.
I have already mounted my ext3 "/" with ext4 driver (it is compatible this way).
Does grub look at kernel image + initramdisk only, which resides on separate /boot partition in my case, or actually looks at "/" too? I have no need to convert /boot :-)

@jpollard: Yes, I am aware of this. But updates will come and eventually files will be overwritten. I hope to gain improvement over time.

Last edited by merilius; 16th July 2012 at 08:47 PM.
Reply With Quote
  #5  
Old 17th July 2012, 11:42 AM
george_toolan Offline
Registered User
 
Join Date: Dec 2006
Posts: 2,078
linuxfirefox
Re: ext3 -> ext4 conversion of "/" and old Grub

Do you have a SSD? The only improvement is the support for the trim command ;-)
Reply With Quote
  #6  
Old 19th July 2012, 12:23 PM
merilius Offline
Registered User
 
Join Date: Jan 2009
Posts: 27
linuxfirefox
Re: ext3 -> ext4 conversion of "/" and old Grub

So, I performed the conversion. Edited fstab, recreated initramfs, booted from some rescue CD based on Gentoo and executed tune2fs and e2fsck. All seems to work fine. Have an impression that yum works faster now (maybe it is not a placebo effect).
Reply With Quote
  #7  
Old 19th July 2012, 04:40 PM
Gareth Jones Offline
Official Gnome 3 Sales Rep. (and Adminstrator)
 
Join Date: Jul 2011
Location: Birmingham, UK
Age: 32
Posts: 2,771
linuxfirefox
Re: ext3 -> ext4 conversion of "/" and old Grub

It might do, as yum is modifying files and installing new ones, so extents may come into play. However, it's worth noting that in recent Fedora kernels, the ext4 driver is used for ext2/3 mounts too. On the whole, it's still worth enabling full ext4 features though.
Reply With Quote
Reply

Tags
>, conversion, ext3, ext4, grub

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
unpredictable "delete" "move to trash" or "cut" file menu option dorianrenato Using Fedora 1 21st November 2011 03:09 AM
Omega "Pug" respin file system (ext4?) robert-e Installation, Upgrades and Live Media 3 25th July 2009 12:10 AM
need help bad with md raid reassembly, or maybe ext4 "group descriptors corrupted" jent Using Fedora 6 31st January 2009 04:13 PM
Error:visibility arg must be one of "default", "hidden", "protected" or "internal" wangfeng Using Fedora 0 23rd May 2005 04:59 AM
root-tail error message:"missing charsets in String to FontSet conversion" ! krazibon3 Using Fedora 0 20th September 2004 04:39 AM


Current GMT-time: 07:31 (Saturday, 01-11-2014)

TopSubscribe to XML RSS for all Threads in all ForumsFedoraForumDotOrg Archive
logo

All trademarks, and forum posts in this site are property of their respective owner(s).
FedoraForum.org is privately owned and is not directly sponsored by the Fedora Project or Red Hat, Inc.

Privacy Policy | Term of Use | Posting Guidelines | Archive | Contact Us | Founding Members

Powered by vBulletin® Copyright ©2000 - 2012, vBulletin Solutions, Inc.

FedoraForum is Powered by RedHat
Nordhausen Photos - Wulfrath Photos on Instagram - Carnaxide Photos