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From: Grant <emailgrant@gmail.com>
To: Tanstaafl <tanstaafl@libertytrek.org>
Cc: Gentoo mailing list <gentoo-user@lists.gentoo.org>
Subject: Re: [gentoo-user] {OT} Need a new server
Date: Sun, 15 Sep 2013 04:15:06 -0700	[thread overview]
Message-ID: <CAN0CFw2+o-W5JphZ7uvVDtrwUcp3macBunUo-6=UM0ae3A=U0A@mail.gmail.com> (raw)
In-Reply-To: <5234494B.9010301@libertytrek.org>

>> http://blog.open-e.com/why-a-hot-spare-hard-disk-is-a-bad-idea/
>>
>> "Based on our long years of experience we have learned that during a
>> RAID rebuild the probability of an additional drive failure is quite
>> high – a rebuild is stressful on the existing drives."
>
> This is NOT true on a RAID 10... a rebuild is only stressful on the other
> drive in the mirrored pair, not the other drives.
>
> But, it is true for that one drive.

Why wouldn't it be true of RAID 10?  Each drive only has one mirror,
so if a drive fails, its only mirror will be stressed by the rebuild
won't it?

> That said, it would be nice is the auto rebuild could be scripted such that
> a backup could be triggered and the auto-rebuild queued until the backup was
> complete.
>
> But, here is the problem there... a backup will stress the drive almost as
> much as the rebuild, because all the rebuild does is read/copy the contents
> of the one drive to the other one (ie, it re-mirrors).
>
>> Instead, how about a 6-drive RAID 10 array with no hot spare?  My
>> guess is this would mean much greater fault-tolerance both overall and
>> during the rebuild process (once a new drive is swapped in).  That
>> would mean not only potentially increased uptime but decreased
>> monitoring responsibility.
>
> I would still prefer a hot spare to not... in the real world, it has saved
> me exactly 3 out of 3 times...

You would prefer 4-drive RAID 10 plus a hot spare to 6-drive RAID 10?
Isn't 6-drive RAID 10 superior in every way except for cost (1 extra
drive)?

- Grant


  reply	other threads:[~2013-09-15 11:15 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-13 20:00 [gentoo-user] {OT} Need a new server Grant
2013-09-13 20:39 ` Alan McKinnon
2013-09-13 21:39   ` Grant
2013-09-14  8:14     ` Alan McKinnon
2013-09-14  8:54       ` Grant
2013-09-14  9:02         ` Alan McKinnon
2013-09-14  9:14           ` Grant
2013-09-13 20:44 ` Michael Orlitzky
2013-09-13 21:47   ` Grant
2013-09-13 22:47     ` Peter Humphrey
2013-09-13 22:54       ` Daniel Frey
2013-09-14  8:50         ` Grant
2013-09-14 11:32           ` Tanstaafl
2013-09-15 11:15             ` Grant [this message]
2013-09-16  9:54               ` Tanstaafl
2013-09-14 14:37           ` Michael Orlitzky
2013-09-16  6:49             ` Grant
2013-09-16 13:10               ` Michael Orlitzky
2013-09-17  6:43                 ` Grant
2013-09-17 12:30                   ` Michael Orlitzky
2013-09-17 13:13                     ` Grant
2013-09-17 16:46                       ` Alan McKinnon
2013-09-13 23:17     ` Michael Orlitzky
2013-09-14  8:52       ` Grant
2013-09-14 11:35     ` Tanstaafl
2013-09-13 21:58 ` thegeezer
2013-09-13 22:14   ` Grant
2013-09-14  8:59 ` [gentoo-user] " Grant
2013-09-14  9:10   ` Alan McKinnon
2013-09-14  9:29     ` Grant
2013-09-14 11:07       ` Michael Hampicke
2013-09-15 11:07         ` Grant
2013-09-14 14:36       ` Alan McKinnon
2013-09-14 11:34     ` Tanstaafl
2013-09-14 14:42       ` Alan McKinnon
2013-09-14 11:04   ` thegeezer
2013-09-15 11:05     ` Grant
2013-09-14 11:18 ` [gentoo-user] " Tanstaafl
2013-09-15 11:10   ` Grant
2013-09-17  5:36     ` Pandu Poluan
2013-09-17  6:32       ` Grant
2013-09-17  9:24       ` Neil Bothwick
2013-09-17 10:01       ` Tanstaafl
2013-09-17  7:28   ` Grant
2013-09-17  7:37     ` Pandu Poluan
2013-09-17  9:49       ` Grant
2013-09-17 10:10         ` Alan McKinnon
2013-09-17 13:11           ` Grant
2013-09-17 16:49             ` Alan McKinnon

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