[mythtv-users] 2 TB Hard Drive Recommendations

Robin Hill myth at robinhill.me.uk
Tue Dec 7 22:22:32 UTC 2010

On Tue Dec 07, 2010 at 04:02:04PM -0500, John Drescher wrote:

> > Note that Green drives are not recommended for raid arrays because of timing
> > out and goofing your raid array.  WD's "RE" (RAID Edition) HDDs support
> > Time-Limited Error Recovery ("TLER" ):
> >
> > More info here:
> >
> > http://www.tomshardware.com/forum/251076-32-raid-issues-western-digital-hard-disk
> >
> > I went WD Black RE's and they are speedy and have been reliable.
> >
> TLER is not necessary on linux software raid or zfs raid. It is needed
> on hardware raid or on windows software raid.
No idea where you get that from.  Linux software raid is certainly
affected by read errors causing long lockups (which TLER dramatically
reduces).  I don't know about ZFS, but I really doubt that it isn't
affected - working around it would be enormously complicated (you'd need
to timeout the read request in the driver and fall back to parity, keep
track of when the drive does actually starts responding again, then deal
with rewriting the bad block, all the time preventing any other read
requests to the drive and keeping track of pending writes).

That's not to say that drives without TLER can't be used though - you
just have to accept the array locking up for 10s of seconds occasionally.

    ( ' }     |       Robin Hill        <myth at robinhill.me.uk>  |
   / / )      | Little Jim says ....                            |
  // !!       |      "He fallen in de water !!"                 |
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