Arch Linux

Kei

Member

Registered: 2007-04-05

Posts: 88

Thoughts about LVM

Hi,

I want to reorganize my data, because right now I've got lots partitions - some of them too small, some of them too big. I want to try LVM. I wonder if it is a good idea to use everything, except the space for root and swap partitions, as one single logical device (/Home). I've got 4 disks in my computer, 250 GB each. So the big fat /Home partition would span across all of them.
Additionally, since I work with a dual boot environment: Has anybody tried Explore2fs (http://www.chrysocome.net/explore2fs)?

LVM users, please share your experiences :-) I'm looking forward to any comments

chicha

Member

From: France

Registered: 2007-04-20

Posts: 271

Re: Thoughts about LVM

Hi !

I am using LVM2 since a few month.
I have 2 hard disks (60 Go and 80 Go) and 2 distros (Kubuntu on 1 disk and Arch on the other)

I have to say that I am VERY happy with LVM

I tested LVM with Kubuntu. I had / and /boot outside the LVM and /home, /var, /usr and /tmp inside the LVM.
I also have a /var/backup and /home/movies inside the LVM.
I leave swap outside the LVM (see http://bbs.archlinux.org/viewtopic.php? … 2#p249592)

When I switched to Arch I changed the configuration. I do not think having a /usr and /boot partition is very important for me.
So I changed every thing : renaming, resizing, moving across the disks .... almost every dangerous and scary operation you can do with a filesystem I did them Without any problem !

Now I have a / partition outside the LVM and /home, /var and /tmp inside the LVM. I also have a /var/backup and /var/movies in the LVM.
On the contrary of what you need, I made 2 different LVM groups so that I am sure that the data are on one single disk. I want to use the other disk as a rescue/backup disk if the first one crashes ...

I hightly recommand to leave / outside the LVM. Technically Arch is able to boot a partition in a LVM if you have LVM in your hook for Mkinitcipio. But when things go wrong you are happy to be able to boot with a floppy or a livecd which does not handle LVM at boot time ... More ever you will certainly never have to change your / . I have a 10 Go / which contain /, /etc, /boot, /opt and /usr. I use KDE, firefox and a lot of tools and 10 Go are more than OK for my needs.

I hope it helped !
Cheers,
Chicha

billy

Member

From: Slovenia

Registered: 2006-09-13

Posts: 164

Re: Thoughts about LVM

i am using LVM and it works. i can't say great here because i haven't try any resizing or moving logical partitions . if i try that i'll let you know. maybe when i get rid of windows partition and set it up as a qemu/kvm image . i'm running lvm on only one disk and have / and /home partitions on it with reiserfs while i left swap and /boot outside. there have been no problems at all and i've been using lvm for half a year now.

i also tried knoppix which mounts my lvm partitions fine if something bad happens.

if you set up lvm, don't forget to edit rc.conf line USELVM="no" to "yes". and if you set it up on root add hook "lvm2" to mkinitcpio.conf (and to *-fallback.conf files) and add this files to NoUpgrade in pacman.conf.

dmartins

Member

Registered: 2006-09-23

Posts: 360

Re: Thoughts about LVM

I use LVM on my file server / mythtv box and love how easy it makes resizing partitions or adding new disks. However, I am always a little wary to have volume groups which contain physical volumes from multiple disks. Maybe I shouldn't worry, but to me that seems like a RAID 0 setup -- one disk dies and all the data is gone (and the chance of this increases with each disk you add).

Can anyone confirm this is the way LVM works when a VG spans multiple disks?

Kei

Member

Registered: 2007-04-05

Posts: 88

Re: Thoughts about LVM

Thanks for your response..

It seems that using LVM is a good idea. My only concern is with creating a LV which spans accross multiple disks, like dmartings said. Does anybody know if I lose all my data if one disk fails? Can anyone point me to a tech doc, where I can find a description how data is put on the disks with LVM?

Thanks again..

btw: why are my postings always shown twice?

//EDIT: lol, now the duplicates are gone.. must have been a problem with my browser cache
But even more funny: I got the reply notification for your post TWICE! Now I think it should be better to have a nap ;-)

Last edited by Kei (2007-05-16 14:37:20)

chicha

Member

From: France

Registered: 2007-04-20

Posts: 271

Re: Thoughts about LVM

btw: why are my postings always shown twice?

Because you drank too much ?
I only see your post once !

riri

Member

Registered: 2007-05-21

Posts: 28

Re: Thoughts about LVM

Mandrake (2001) -> Debian (2002) -> Nasgaia (2003) -> LFS (2004) -> FreeBSD (2004) -> Gentoo (2005) -> Kubuntu (2006) -> Archlinux (2007) -> ?
Will Archlinux finally be THE distro of my dreams ? Time will say, but its on the way cool

Maybe Nasgaïa will be when in the boxes ;-)

Sure for now, Archlinux is a good distribution, as many others; just a matter of taste.