UFS2 with 4TB disk _totally absurd_

[Ensel Sharon]

On Thu, 6 Apr 2006, Scott Long wrote:

> Ensel Sharon wrote:
> >>The FDISK and bsdlabel schemes simply cannot deal with >2TB.  You'll
> >>need to either put your filesystem directly on the storage device
> >>without and slices/labels, or use GPT to create logical partitions.
> >
> >
> > 2TB filesystems are _not large_.  FreeBSD should expect 2-4TB
filesystems
> > to be in common use in peoples _living rooms_, never mind in the
office or
> > datacenter.
> >
> > So 5.x was a total wash in terms of UFS2 and snapshots, largefiles,
etc.,
> > 6.0 still doesn't have working filesystem quotas or snapshots, and it
> > seems, doesn't support modern (circa 2004) hard drives.
> >
> > Maybe a little less time working on FreeBSD 23.0 ... ?
> >
>
> What are you talking about?  UFS2, the filesystem, supports storage
> volumes up to 2^63 blocks in size, and filesystems themselves of
> more than 2^53 blocks in size.  There is no 2TB limit in UFS2, and I've
> personally created filesystems that are indeed much larger than that..
> These sizes were supported in 2004, and they are supported in 2006.
> What is limited is the FDISK and BSDLABEL formats, which were designed
> in the early 80's to handle up to 2^32 blocks.  Neither of these prevent
> you from creating a large filesystem.  Maybe you're looking to have a
> single large volume to hold both your boot filesystem and your data
> filesystem?  That's generally a bad idea since it puts more things into
> the path of a failure.  Try doing what most people do, which is to boot
> off of a 2 disk mirror (go big and get 500GB disks if you want) and have
> your data on a separate array that is more redundant and doesn't need to
> use the above partition formats.
>
> Alternatively, find a PC that understands how to boot off of GPT
> partitions, and use that format.  It's not FreeBSD's fault that the PC
> BIOS uses the FDISK format.  Go complain to IBM and Microsoft for not
> having the foresight to future-proof their partition format 25 years
> ago.


I'm not saying that you can't create 2+ TB filesystems.  I am saying that
there are all sorts of problems with them, from snapshotting them, to
fsck, to easy creation with sysinstall.

And all the while, the reaction has been a non-chalant dismissiveness,
presumably based on the fact that 2+ TB filesystems are out of the norm,
or are "frontier" hardware or whatever.  I am writing to inform you that
that is not the case, and has not been for quite some time.  I know many
people with 2+ TB filesystems in their houses - I have one _attached to my
television_.

So whereas the fact that fsck and snapshots and dump and restore and df
and quotas are all broken on 2+ TB:

http://www.freebsd.org/projects/bigdisk/index.html

The thought was that that would get cleaned up circa 5.2 or
something.  Here we are at 6.1 and it's still broken.  Perhaps when
commodity disks exceed 50% of the size of the max known-working FreeBSD
partition the urgency will increase ?