Archived posting to the Leica Users Group, 2009/07/31

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Subject: [Leica] Seagate
From: jbm at jbm.org (Jeff Moore)
Date: Fri, 31 Jul 2009 17:01:13 -0400
References: <200907311902.BSU39530@rg4.comporium.net> <c7c8cf880907311227kbc4ece5wc1f4b8b11d268495@mail.gmail.com> <200907311938.BSU43042@rg4.comporium.net> <1ADB92E8-CFFC-4C70-A0C3-9AA83EE5D972@frozenlight.eu> <7ac27f4f0907311312o749c4d95tdf17a7dc0230da58@mail.gmail.com> <EA3E2C6F-5091-4E2C-90FA-135ED2FD8049@frozenlight.eu>

2009-07-31-16:46:00 Nathan Wajsman:
> Do you mean both discs failed at the same time (I am assuming it was a  
> RAID 1 configuration)? Of course it can happen, but the probability is  
> tiny compared with the probability of one disc going bad.

Yeah.  Some systemic failure, involving some component other than a
disk, is always possible, and it's possible that such a failure might
scribble garbage on more than one disk, but most often it seems as if
one drive goes at a time.

I mean, jeez, I hope he was using a redundant configuration rather than
some stripe arrangement without redundancy.  Of course, if you stripe a
couple of drives together to get the space and speed of both, you're
reducing reliability.  But nobody who's concerned with safe archiving
would do it that way.

In my beloved ReadyNAS NV, I've been through two generations of disks
(replacing dead ones, and eventually migrating to larger ones, all while
maintaining the integrity of the data).  One secret is: always have at
least one replacement drive on hand, so you can replace a failed drive
immediately, and let the array rebuild including the new drive --
because sometimes, if your drives are the same model (and especially
production batch), failures might cluster around the same number of
hours;  but you *usually* get a window for rolling in a replacement.

Oh, another thing, which I forgot to mention:  if you use drives
anywhere near all the time, and have an enclosure with proper cooling,
set things up so they never stop spinning.  Spin-ups seem to kill drives
faster than just keeping them rolling.

 -Jeff


In reply to: Message from images at comporium.net (Tina Manley) ([Leica] Seagate)
Message from pasvorn at boonmark.net (Pasvorn Boonmark) ([Leica] Seagate)
Message from images at comporium.net (Tina Manley) ([Leica] Seagate)
Message from photo at frozenlight.eu (Nathan Wajsman) ([Leica] Seagate)
Message from richard.lists at gmail.com (Richard Man) ([Leica] Seagate)
Message from photo at frozenlight.eu (Nathan Wajsman) ([Leica] Seagate)