On Wednesday 25 May 2005 15:45, Dave Jones wrote:
On Wed, May 25, 2005 at 03:38:22PM -0700, David Kewley wrote:
> Can anyone here provide experience reports or pointers to reports,
> regarding the safety of Linux's write support for Sun UFS? It is
> marked as experimental and dangerous, but it appears to have been
> around since 1998. I'm wondering whether this might be one of
> those things that works fine but still carries old labels.
It doesn't get any real attention upstream, so I've no particular
belief that its gotten any more stable than it ever was (wrt writes).
For this reason, the write support is disabled in Fedora.
> I have several external RAID arrays that up to now have been
> attached to Sun boxes and formatted with UFS filesystems. I will
> be attaching these arrays now to a RHEL 4 host.
UFS is also unavailable in RHEL4.
> If I can safely get away with it, I'd prefer to keep writing to
> the UFS volumes since we're talking about several TB of data.
I certainly wouldn't trust it with data I wanted to keep.
> then I will need to transfer the data to a Linux filesystem with
> spare TB of space, reformat the external filesystems, and move the
> data back (or variations on that plan). These are filesystems
> that several people use for daily work, so I'd rather avoid the
> copy time if possible.
This is unfortunatly, probably the best way forward.
Thanks *very* much, Dave -- it's good to hear this from someone highly
involved in the kernel. I'll take your advice.
I am using UFS and XFS in RHEL4 by rebuilding the kernel with those
filesystems enabled. The filesystems appear to work fine; I know
others are also using XFS in RHEL4.
I've just now for the first time mounted that Sun UFS volume with this
kernel. I was able to do the one thing I tried -- 'ls' the top-level
directory. :) I had enabled write support in the kernel and mounted it
rw; I'm now going back & re-building that kernel without write support,
per your advice. I could mount ro, but that's not as safe as disabling
writes.
I know that using these filesystems on RHEL4 is neither supported nor
recommended by Red Hat. As an academic site-license customer, however,
I don't get RH support anyway, so I get to make my own choices
appropriate to my risk tolerance. ;)
David