[mythtv-users] filesystem choice for an 8TB logical drive.

[John Drescher]

On Mon, Oct 19, 2009 at 10:28 AM, Andy Colson <andy at squeakycode.net> wrote:
> David Knight wrote:
>>
>> On Mon, October 19, 2009 1:34 am, Jean-Yves Avenard wrote:
>>>
>>> 2009/10/19 Greg Grotsky <spikeygg at gmail.com>:
>>>
>>>> 1) plug in the new drive.
>>>> 2) create a pv, vg, and lv on the new drive.
>>>> 3) copy all the movies from the�jfs�drive to the new lv.
>>>> 4) wipe the partition info and create and LVM partition on it.
>>>> 5) extend the new lv onto the old disk.
>>>> 6) extend the filesystem.
>>>> (let me know if I'm missing anything here)
>>>>
>>>> Because of this I need to use a filesystem that can be resized.� I know
>>>> that
>>>> JFS can but I worry that it can not be shrunk (I'm not sure why).
>>>
>>> The more valid question may be, how likely are you going to want to
>>> shrink a partition size?
>>>
>>> I run 5x 1.5TB in raid5 + LVM + JFS
>>>
>>> no trouble here
>>>
>>> one of my 1.5TB died after only 4 months, got it replaced under
>>> warranty, glad I had RAID
>>>
>>>
>>
>> I've just converted to 3 x 1TB in raid 5 + LVM + XFS, thoroughly
>> recommended.
>>
>
> Just as a curious question, having never used LVM, if you can add disks to
> raid5, and the filesystem (jfs/xfs) can be grown, what does lvm give you
> that you didnt already have?
>

I use LVM on all systems (home and work) for the last 5 years. It
allows you to connect multiple RAIDs together to a single volume. BTW
I said RAIDs, because I would never use it to span individual disks.

LVM also makes it easy to shrink and expand filesystems. Although if
you are just going to make a single file system this is not an
advantage. I never use a single filesystem on any of my dozens of
LVMs. On home mythbox, I have 5 to 7 hard drives (not sure how many
are plugged in), anyways each of these drives has its own lvm. The 2TB
WD Green drive has an LVM with 3 x 500GB ext4 filesystems I have in my
storage groups and also some space for my downloads and isos.

John