Re: [gentoo-user] LVM for data drives but not the OS

[Joost Roeleveld]

On Thursday 07 April 2011 06:12:40 Dale wrote:
> Joost Roeleveld wrote:
> > On Thursday 07 April 2011 05:22:41 Dale wrote:
> > You will need to do it in the following steps though:
> > - create PV, LVM and LV on the new drive
> > - copy data over
> > - create PV on old drive and add it to LVM
> > Contact me or list if you need help with the actual commands and syntax.
> > (There are plenty of howtos around)
>
> I was reading the howto on a couple sites and it sounded like this could
> be done.  Glad to know I would have to copy the files over to a LVM
> drive tho.  That info was something I didn't know.  I was hoping for
> some magic.  lol

As far as I know, there is no "automatic conversion tool" for most of these.
Switching from non-raid to RAID-1 (mirroring) is the only one I think that 
might work.

> >> I want to do it this way because I don't trust LVM enough to put my OS
> >> on.  Just my personal opinion on LVM.
> >
> > Interesting argument. You don't trust LVM, so you put your personal
> > files on there, but not the easily replacable stuff like OS? :)
>
> I like my OS setup and don't want to have to reinstall.  Although Gentoo
> has never let me down yet, I don't want to add to the confusion.  If I
> can boot and get to my email, I can get help to fix LVM if needed.  I
> also keep a backup of my personal files.  I could recover the things I
> don't backup tho.  Most of my concern is my lack of experience with
> LVM.  If I was a guru on it, I might feel better about it.

Worst case I had: the metadata was incorrect. This was back with 2.6.18 
kernels though.
That was also easily recovered as all the LVM-tools, with default 
configuration, backup the metadata to a text-file before/after making any 
chances.
You can then easily recover if anything goes wrong :)

> > Please note, I have not lost data related to issues with LVM. I have, in
> > the distant past, lost data related to issues with filesystems.
> > Because of the latter, I rely on a combination of RAID-subsystems with
> > LVM on top and reliable backups :)
> >
> > --
> > Joost Roeleveld
>
> Unless someone has a better idea, I think LVM is about all I can find
> that would do this.  The drives won't be even close to each other.  I
> hope I can find a nice 2Tb drive that I can afford.  ;-)  Maybe that
> will last a while.  The 750Gb drive did last a pretty good while. I'm
> not sure after that tho.

I've got 6 * 1.5TB drives in RAID-5 for documents and media and we have about 
2TB left. But with our usage, I'll probably have to look into extending that 
later this year.

> Thanks for the info.  It did add to my knowledge and settle one of my
> questions.

Always glad to help.

--
Joost