[mythtv-users] Problems with External USB Drives

[James Crow]

On Wed, 2008-11-26 at 11:09 -0600, Jonno wrote:
> On Wed, Nov 26, 2008 at 9:36 AM, John Drescher <drescherjm at gmail.com> wrote:
> > On Wed, Nov 26, 2008 at 10:29 AM, Mike Holden <mythtv at mikeholden.org> wrote:
> >> Jonno wrote:
> >>> Well the frag level did drop from 99.38% to 99.29% so I guess I will
> >>> keep trying for a while and see what progress I can make. Also I've
> >>> tried to run spinrite (grc.com) on the drive to see if there were
> >>> sector problems but with a 750GB drive via external USB it was gonna
> >>> take weeks.
> >>
> >> Is it possible to remove it from the external enclosure and plug in
> >> directly to the mobo?
> >>
> > That will probably void the warranty and to me this looks like the drive is bad.
> 
> I bought the drive separate from the enclosure so that's not a
> problem. However it's a pain in the butt. So far the defrag runs for a
> while and then freezes up. I'm down to 99.17% now. I may try deleting
> a bunch of old recordings to make some more space and then run defrag.
> Are there any other built-in linux commands for checking a disk for
> errors for example?

With an xfs drive used only for recordings you could change the
allocation size to 256M, 512M, or 1G and it would almost defrag itself
from the normal deletion of recordings.

I have my 500GB drive set to 1G and saw the frag level drop from high
80% range down under 30%. I only use this drive for recordings so 1G
seemed appropriate.

With xfs defrag if it cannot move a file due to space constraints it
will print an error and continue. Say 5GB free and a 2 hour HD recording
that is fragmented.

When I first started having i/o issues I ran xfs_fsr for over 10 hours
while myth was not recording to drop the level to 60% or so. I let
things go for a week or so and the level was back to 80%. I then changed
the alloc size to 1G and that had more impact than anything else. Skip
the xfs_fsr run and just change your alloc size to an appropriate value.
Default is 64kb.

This info is also not currently useful for you if the hardware is bad.
Connect the drive to the motherboard and then run the manufacturers
tools to check it. Most of them provide a download of a bootable iso you
can use. It also helps with geting the drive replaced because you have
the error reported from their tools.

Cheers,
James