From: David Brown <david.brown@hesbynett.no>
To: Adam Goryachev <mailinglists@websitemanagers.com.au>
Cc: Guillaume Betous <guillaume.betous@gmail.com>,
linux-raid <linux-raid@vger.kernel.org>
Subject: Re: Best practice for setting up "ordinary" RAID
Date: Fri, 11 Oct 2013 11:31:18 +0200 [thread overview]
Message-ID: <5257C566.6040208@hesbynett.no> (raw)
In-Reply-To: <5257A333.2010809@websitemanagers.com.au>
On 11/10/13 09:05, Adam Goryachev wrote:
> On 11/10/13 17:52, Guillaume Betous wrote:
>>> RAID6, preferrably with a spare.
>> I'm not comfortable with RAID 6 setup. What is the minimal number of
>> hard drives for having a RAID 6 + spare ?
>>
>
> Check wikipedia, but minimum of 4 drives for RAID6, consider 2 data
> drives plus two redundant drives, allowing you to lose any two drives
> (slightly better than RAID10 on 4 drives).
>
> In direct answer, RAID6 + hot spare is a minimum of 5 drives.
>
That's just the /sensible/ answer. The minimum is actually 4 drives -
one data, two redundant, and one spare (though obviously there are
better ways to use your drives). And with mdadm, you can tell it that
three of these drives are missing. While such things might seem a bit
silly, it is sometimes convenient to get your raid up and running with
the setup you want even if you haven't physically got the drives in
place yet - you can add them in later.
next prev parent reply other threads:[~2013-10-11 9:31 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-11 6:10 Best practice for setting up "ordinary" RAID Guillaume Betous
2013-10-11 6:35 ` Mikael Abrahamsson
2013-10-11 6:52 ` Guillaume Betous
2013-10-11 7:03 ` Mikael Abrahamsson
2013-10-11 7:14 ` Guillaume Betous
2013-10-11 7:19 ` Mikael Abrahamsson
2013-10-11 8:58 ` Guillaume Betous
2013-10-11 8:15 ` Robin Hill
2013-10-11 8:57 ` Guillaume Betous
2013-10-11 9:28 ` David Brown
2013-10-11 7:05 ` Adam Goryachev
2013-10-11 9:31 ` David Brown [this message]
2013-10-11 9:53 ` Guillaume Betous
2013-10-11 14:04 ` David Brown
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5257C566.6040208@hesbynett.no \
--to=david.brown@hesbynett.no \
--cc=guillaume.betous@gmail.com \
--cc=linux-raid@vger.kernel.org \
--cc=mailinglists@websitemanagers.com.au \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox