Changing filesystem type in Linux

[user1234]

I have a Debian based Linux installation on a partition which is using the ext3 filesystem currently. I would like to preserve everything, but move to ReiserFS filesystem. My plan is to create a new partition with ReiserFS and copy all the files from the existing partition using "cp -rp /mnt/old_part/* /mnt/new_part" (during the copy I will have a different partition mounted as the root filesystem). My question is if I would need to edit any configuration files to be able to boot with the new partition as the root filesystem. Probably fstab, but what else ?

 

[n0cmonkey]

fstab and your bootloader configuration (lilo.conf/grub.conf or whatever)

Do a search on this. I think there is an "archive" flag for GNUcp that might be better than just an "-rp." I'd check the manpage, but I'm lazy. 😉

 

[Haden]

What n0c said,
also you don't need to have different partition mounted as root, "cp -ax / /mnt/new_hdd" will do the work, then chroot to /mnt/new_hdd, edit bootloader config and rerun bootloader.
Plus, as you will edit your bootloader (I assume lilo) config - don't forget to edit it after booting to new system if disks swap (e.g. /dev/hdc changes to /dev/hda).

 

[n0cmonkey]

Oooh oooh! Make sure you run /sbin/lilo (if you're using lilo 😛 ) after you edit the config. I almost always forget that. 😛

Usually when I read manuals on moving partitions and whatnot, they recommend being in single user mode, so that's something to consider.

 

[user1234]

Thanks. I see that you emphasize the boot loader issues, but I think that's the easy part. I use grub, and I'm planning to boot from a knoppix live cd, and create the new partition, format its filesystem, and do the copy from there, and then add an entry in my normal hardisk bootloader configuration. Btw, I also have another partition with a minimal linux install (1GB, no X), which also stores the grub configuration files, so I can always boot from there if I need to. This might be faster than working with the live CD, but knoppix gives the nice partioning tool and the graphical interface. I know many people manage to screw up their system when they mess around with partitions and boot configurations, because they do not plan for alternative boot methods. But with today's tools (especially linux live rescue CDs), this should not be a problem.

 

[n0cmonkey]

Originally posted by: user1234
Thanks. I see that you emphasize the boot loader issues, but I think that's the easy part. I use grub, and I'm planning to boot from a knoppix live cd, and create the new partition, format its filesystem, and do the copy from there, and then add an entry in my normal hardisk bootloader configuration. Btw, I also have another partition with a minimal linux install (1GB, no X), which also stores the grub configuration files, so I can always boot from there if I need to. This might be faster than working with the live CD, but knoppix gives the nice partioning tool and the graphical interface. I know many people manage to screw up their system when they mess around with partitions and boot configurations, because they do not plan for alternative boot methods. But with today's tools (especially linux live rescue CDs), this should not be a problem.

I emphasize the easy because the "elite" typically overlook it. 😉

 

[Nothinman]

I would avoid reiserfs, if you really don't want to use ext3 use something like XFS instead.

 

[silverpig]

I'm running reiser4 on my /home partition. It's nice 🙂

Oh, and you can also just do a dd if=/dev/hdXY of=/dev/hdWZ too I think.

 

[user1234]

Originally posted by: Nothinman
I would avoid reiserfs, if you really don't want to use ext3 use something like XFS instead.

please explain....

I want whatever can give me the most performance. The main uses of this machine are web browsing, linux configuration stuff including compiling, personal productivity apps (open office), and multimedia playback (dvds, cds, mp3). BTW, it's an Athlon XP 3200+ with Nvidia nForce2 IGP (integrated graphics) chipset and 512 MB of RAM.

 

[user1234]

are you sure dd would work between two different file systems ?

 

[Nothinman]

No dd won't do any conversion, if you dd the whole block device you get the data and the filesystem. You have to use something like tar or cpio to get just the files.

please explain....

Hans Reiser is an ass and his filesystem isn't worth the potential trouble. Everytime I try it something eventually goes wrong that's the fault of the filesystem, the same isn't true of ext2, ext3 or XFS.

 

[n0cmonkey]

Originally posted by: Nothinman
No dd won't do any conversion, if you dd the whole block device you get the data and the filesystem. You have to use something like tar or cpio to get just the files.

please explain....

Hans Reiser is an ass and his filesystem isn't worth the potential trouble. Everytime I try it something eventually goes wrong that's the fault of the filesystem, the same isn't true of ext2, ext3 or XFS.

The revolutionary ideas might be worth it. If your data isn't important. 😉

 

[user1234]

Which filesystem has the best performance ?

 

[Nothinman]

XFS was designed for huge filesystems and huge files, SGI is/was big in the A/V processing business, while reiserfs was designed to be really fast with small (<4K) files and large numbers of them. I'm sure a number of people will chime and say "reiserfs works fine for me", but I just don't think the risk is worth it. XFS has similar if not better performance and is a lot more reliable IME.

 

[Sunner]

Originally posted by: Nothinman
XFS was designed for huge filesystems and huge files, SGI is/was big in the A/V processing business, while reiserfs was designed to be really fast with small (<4K) files and large numbers of them. I'm sure a number of people will chime and say "reiserfs works fine for me", but I just don't think the risk is worth it. XFS has similar if not better performance and is a lot more reliable IME.

So long as your kernel supports it out of the box, I agree.
A Debian/Stable won't however, support was added in 2.4.24, right? Or was it 2.4.26?

For a workstation that doesn't have 24/7 uptime demands, I'd say ReiserFS is good enough, though I wouldn't trust something critical to it.

 

[Nothinman]

A Debian/Stable won't however, support was added in 2.4.24, right? Or was it 2.4.26?

Debian stable is only for if you're extremely paranoid or something, the new sarge installer supports a 2.6 kernel and the partitioner has XFS (and other) filesystem support now.

 

[drag]

One thing about XFS and ReiserFS (3) and other linux file systems is that they put lots of effort into file system integrity, however they don't worry much about individual files.

Ext3 (and ReiserFS 4, since it's atomic file operations don't require any logging or whatnot) cares about data integrity. For example if you have a crash due to harddrive hardware crash it will probably spring into ext2-style mode and scan the entire file system for inconsistances. Otherwise with normal power outages it will do a quick journal check like what is used in JFS/XFS/Reiserfs3.

(not handling hardware failers/power outages and hardlocks with a e2fsk-type tool is one of the reasons that reiserfs 3 got a bad reputation. It's file system (metadata) would always be right, but the files in it may suffer)

So with XFS, ReiserFS 3, and JFS you don't have to worry about your entire system corrupting, but if you have a power outage you may end up with 1 or 2 corrupt files that you may accidently run into, but ext3 will find those files and attempt to do something about them.

This is one of the reasons that Redhat still uses ext3 for it's enterprise systems.

slighty older article.

again:
<a target=_blank class=ftalternatingbarlinklarge href="https://www.redhat.com/archives/roswell-list/2001-August/msg01024.html">https://www.redhat.com/arch......gust/msg01024.html</a>

why ext3

Personally I use XFS for my desktop because I want the large file performance, however for my laptop I use Ext3 because it's more likely to have power outages (oops) and be jostled. Seems to me for best file system stability in Linux right now ext3 in ordered mode seems to be the best bet.

Of course keep in mind that Redhat did do the developing for ext3, so it's their baby.