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

[John Drescher]

On Sun, Oct 18, 2009 at 7:17 PM, Greg Grotsky <spikeygg at gmail.com> wrote:
> To all interested,
>
> I recently (two weeks ago) purchased a 2TB WD HDD from Newegg.  It was my
> wife's birthday present... she loves her movie collection.  I formatted it
> with jfs because I read lots of good things about it's large file
> performance.  I've been ripping DVDs steadily and so far I'm ~270 down but
> the drive is getting full and I have about 75 to go!  Unfortunately, I don't
> have enough space to finish our collection!  Just today I purchased another
> 2TB drive and I'm planning on building it into a 4TB LVM.  Since I've
> already got 2TB of data on one I have to:
>
> 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).
>
> My questions are:
> 1) Should I be worried that I cannot shrink JFS?
> 2) Should I use another filesystem type because I cannot shrink JFS, or for
> some other reason?
> 3) I've read some things about ext4 which make it sound very appealing.  Has
> anyone had experience growing an ext4 fs to 4TB?
>
> I want to be able to add much more space in the future, so I don't want to
> be limited on resizing.  I've been reading about ext4, and apparently there
> is a 4TB soft limit on fs resizing; the article below talks about some
> META_BG feature but I have no idea what that means.
> http://ext4.wiki.kernel.org/index.php/Frequently_Asked_Questions#How_to_online_resize_the_Ext4_filesystem.3F
>

I see that you said you were ripping dvds so it looks like you can
replace everything if one drive dies rendering most data on the LVM as
unrecoverable. Anyways, I have moved to ext4 for all my recordings. It
has xfs speed with large files but is as at least fast as ext3 with
small files. One other advantage of ext4 is you can shrink the
filesystem while xfs does not allow that.

John