Re: experience with very large filesystems

[Dave Chinner <david@fromorbit.com>]

On Thu, Feb 24, 2022 at 01:09:53PM +0100, Emmanuel Florac wrote:
> Le Thu, 24 Feb 2022 08:10:06 +1100
> Dave Chinner <david@fromorbit.com> écrivait:
> 
> > From the storage side, you really want to expand the storage with
> > chunks that have the same geometry (stripe unit and stripe width)
> > so that it doesn't screw up the alignment of the filesystem to the
> > new storage.
> 
> That part should be easy, I plan to use the same type of hardware anyway
> (12 TB Ultrastar disks).
>  
> > And that's where the difficultly may lie. If the existing storage
> > volume the filesystem sits on doesn't end exactly on a stripe width
> > boundary, you're going to have to offset the start of the new
> > storage volumes part way into the first stripe width in the volumes
> > to ensure that when the filesystem expands, then end of the first
> > stripe width in the new volume is exactly where the filesystem
> > expects it to be.
> 
> That should be somewhat more manageable given that I've setup
> everything as an LVM volume. I may use partitions on the new devices to
> precisely align the PVs before expanding the LV. 

You can use the PV/LV header size options to align the contents of
the LV.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com