[mythtv-users] Problems with External USB Drives
klein.aaron at gmail.com
Mon Dec 1 19:23:13 UTC 2008
> 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.
For the help of others including myself could you quickly outline how
one would adjust the allocation size to something other than the
default. I can see how a large file size would be of benifit for
disks that only stored recordings. This is my exact case. I have two
myth boxes both with 500G drives dedicated exclusivly for recordings.
For me a 30 min recording is about 1gig in size
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