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

[Dale]

Joost Roeleveld wrote:
> On Thursday 07 April 2011 05:22:41 Dale wrote:
>
>> Hi,
>>
>> Quick question about LVM.  I have a 750Gb drive that has miscellaneous
>> stuff on it.  Stuff likes videos, music, pictures, ISO files and a few
>> other things.  It's not full yet but it is working on it.  I have my OS
>> on sda.  The large drive is on sdc.  If I buy another drive it should be
>> sdd.  I think this is possible from what I have read but want to make
>> sure.  Could I put sdc and sdd on LVM but the OS remain as it is with
>> LVM not involved at all?  Basically, my OS stays just like it is and is
>> not touched my LVM at all but the two larger drives are managed by LVM.
>>
> Simple (and complete answer): Yes, you can use LVM only for a subset of the
> drives you have inside a system.
>
> 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

>> 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.

>> If there is a better solution to link two large drives, I'm open to
>> those ideas as well.  LVM is all I can think of is why I mention it.
>>
> RAID-0 (if they're same size) or linking them together.
> Compared to those, I would always recommend LVM as that is easier to maintain
> then JBOD or RAID-0.
>
> There might also be filesystems that include disk-spanning, but if you're
> already not convinced about LVM being reliable, I wouldn't use one of these
> filesystems then.
>
> 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.

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

Dale

:-)  :-)