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

[Dale]

Joost Roeleveld wrote:
> On Saturday 09 April 2011 06:43:25 Dale wrote:
>
>> Alan McKinnon wrote:
>>
>>> Apparently, though unproven, at 12:48 on Saturday 09 April 2011, Dale
>>> did
>>> opine thusly:
>>> Yes.
>>>
>>> PVs, VGs, LVs all have a concept of extend|resize|reduce. What that
>>> means
>>> depends on what you are working with, but they all make the thing bigger
>>> or smaller.
>>>
>>> For a PV it means the underlying device's size changed, so the PV must
>>> change to match. Take a 500G drive, create 1 partition on it of 100G
>>> and make it a PV. Now enlarge the partition to 200G, you must extend
>>> the PV to match.
>>>
>>> A VG isn't a single thing, it's a collection of things. Extending it
>>> means to add more PVs, reducing it means to take PVs out of the VG.
>>> Hopefully you will always remember to migrate the data off a PV before
>>> removing it from a VG :-)
>>>
>>> Extend/Reduce an LV means to make the device larger/smaller. It is
>>> exactly the same thing as changing a partition size using fdisk.
>>> Obviously, you need to tweak the filesystem at the same time
>>>
>> So, when I get me a new drive, I use pvcreate to get it ready for LVM,
>> then use vgextend to add it to the VG, then it is available for whatever
>> LV I want to extend or to make a new LV?
>>
>> I think I am catching on here.  It was just difficult for me to grasp
>> how things are layered for some reason.  Some of the pictures I found
>> helped a good bit tho.  Just helped me picture what the commands are
>> doing exactly.
>>
>> I did learn the hard way to resize the file system tho.  I forgot that
>> earlier.  Sort of had me scratching my head for a bit.  lol
>>
> That's an easy one to miss :)
>
> You do seem to be catching on quick on this.
>
> --
> Joost
>
>

I think I am too.  Since folks know I am disabled anyway, I went to the 
Dr the other day.  The new meds aren't perfect but it is better.  When I 
go back, he may change it to another med.  He just wanted to try this 
first.  It does sort of help me to get a better grasp on things tho.  
Sort of weird in a way.  That part is like a side effect.  :/

I'm just needing to find me a good LARGE drive to put in here.  I'm 
checking out the reviews but it just seems most have issues.  May just 
have to buy one, work the stuffing out of it with a script or something 
to see if it holds up.

I see some of the large drives spin slower, some a lot slower.  Given 
the density of the data, are they about as fast as a drive that spins at 
7200?  My main drives for my OS and the large drive I already have turn 
at 7200 rpms.  I'm just curious if that would be slower or because of 
the density of the data, it doesn't matter.  I get about 80 to 100Mb/sec 
on my current drives.  I have 3gbs/sec drives which is what my mobo 
maxes out at.  I thought about getting a 6Gb/sec just in case I upgrade 
my mobo later.

My data drive mostly has audio/video stuff but does contain pictures I 
took with my camera and some documents, mostly saved web pages or OOo 
stuff.  My 750Gb drives plays audio/video stuff just fine, even the HD 
stuff.  I just wouldn't want to get a drive that is slow enough to cause 
pauses and such.

I see newegg has 3Tb drives too.  he he he he  O_O

Thoughts?

Dale

:-)  :-)