--- On Fri, 5/2/08, Kasper Sandberg <lkml@metanurb.dk> wrote:

From: Kasper Sandberg <redacted>
Subject: Re: Sharing disks amoung multiple software RAIDs
To: "David Greaves" <redacted>
Cc: "David Rees" <redacted>, "David Lethe" <redacted>, alex14641@yahoo.com, "Justin Piszcz" <redacted>, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org
Date: Friday, May 2, 2008, 5:43 PM
On Fri, 2008-05-02 at 09:25 +0100, David Greaves wrote:

quoted

Kasper Sandberg wrote:

quoted

Im not treating it as a backup, what i want, is

to make sure that if 1

quoted

quoted

disk dies, the data is still intact and ill

hopefully be able to run

quoted

quoted

with 1 disk till the newly ordered one arrives

Probably one of the main design objectives behind

RAID/md

Exactly, but once people start saying: "Look how many
problems people
post to the thread on
a weekly basis where people lose their data when md
rebuilds go bad with
non-shared disks" i begin to worry..

quoted

quoted

So my question remains.. Is md raid1 not suited

for this need? would it

quoted

quoted

be safer to run in non-raid1 mode and daily(maybe

hourly) rsync

quoted

quoted

everything over to the second disk?

md is 100% guaranteed perfect or your money back...
rsync is 100% guaranteed perfect or your money back...
your backups are 100% guaranteed perfect or your money

back...

quoted

your hard drives are 100% guaranteed perfect or your

money back...

quoted

your CPU and RAM are 100% guaranteed perfect or your

money back...

quoted

your CPU and PSU fans are 100% guaranteed perfect or

your money back...

quoted

Clearly if you want to panic over reliability you have

lots of choices :)

I do not wish to panic, i merely wished to know if linux MD
is believed
to work in most cases, or believed to do all sorts of weird
stuff when
resyncing :)

quoted

David
PS, FWIW md has saved my data* countless times over

the past 'n' years in

quoted

exactly the scenario you describe.

It has also been useful to people i know, i just wished to
be sure :)
and as Keld Jørn Simonsen and Helge Hafting's comments
seems to confirm,
linux md IS nice and stable :)

and as said, what im looking for isnt an in-box backup
solution, merely
safety in case one disk burns :)

quoted

*(or more accurately has saved me from having to

restore my data)

Just to add another data point, I've been using md in RAID 5 configuration for ~3 years with dedicated USB and SATA disks 
(not mixed) and have had disks go bad, and have yet to lose 
any data. Given the 'quality' of high-capacity disks nowadays,
RAIDing them is the right thing to do.


      ____________________________________________________________________________________
Be a better friend, newshound, and 
know-it-all with Yahoo! Mobile.  Try it now.  http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ