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From: Roy Sigurd Karlsbakk <roy@karlsbakk.net>
To: Chris Jones <cmsj@tenshu.net>
Cc: linux-raid@vger.kernel.org
Subject: Re: RAID10 layout question
Date: Fri, 15 Feb 2013 19:58:10 +0100 (CET)	[thread overview]
Message-ID: <29203573.10.1360954690174.JavaMail.root@zimbra> (raw)
In-Reply-To: <A1B82B87-68E8-4E6A-BF67-B1DCD85FE376@tenshu.net>

> 2) Will I take a performance hit if I manually make two RAID1 sets and
> then a RAID0 of them?

I'd rather use separate mirrors (raid1) and use lvm on top of that - better flexibility.

> 3) Should I forget about the layout and just use RAID6?

Depends what you need. RAID-6 will give you lower IOPS, but better sequencial I/O. It will also stand *any* two drives failing, while striped mirrors (raid-10 or raid-1 with raid-0/lvm on top) will only tolerate a single drive failing per mirror. The chances of two drives failing at the same time is low, but it's rather common to see a single drive failing and then seeing bad data on another drive. If not scterc (smartctl etc) is enabled, or the timeout (/sys/block/$dev/device/timeout) hasn't been increased, a single bad sector may make md kick out a drive, which would be bad if it's rebuilding a mirror. Personally, I use RAID-6 - it's safe and fast enough for my needs.

Vennlige hilsener / Best regards

roy
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      reply	other threads:[~2013-02-15 18:58 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-15 11:45 RAID10 layout question Chris Jones
2013-02-15 18:58 ` Roy Sigurd Karlsbakk [this message]

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