Re: High Availability Options

From: Yury Velikanov <j.velikanovs_at_gmail.com>
Date: Wed, 27 Oct 2010 20:54:30 +1100
Message-ID: <AANLkTinNhFgS8Ey1aQJzVsOGspE6b+xm3WNv8cKQ0BpG_at_mail.gmail.com>



+1 IMHO: both udev or ASM Lib just useless. Why we should introduse any additional layers when we can avoid those. Keep it simple. Use devices directly (ASM will read headers for you, just set the discovery string right) + rc.local will fix privileges esely.

Just my .2$,
Yurt

On Wednesday, 27 October 2010, Amaral, Rui <Rui.Amaral_at_tdsecurities.com> wrote:
> Personally, I would suggest staying away from udev.
>
> My reason for saying this - udev has issues with multipath devices. I spent a couple of weeks some 18 months ago trying to get this implemented and failed. Digging through various linux forums dug up a bug with udev and mpio (maybe that's why the rawdevices was still available in rhel5 but that's just a guess).
>
> In terms of asmlib - I too would stay away from it. I used it in many places until I had my problem (which I mentioned in a previous thread). My asm outage was using asmlib. I had asm on raw and none of those had problems (all large installations) beyond silly stuff like packet collisions on shared i/o ports on the san and such. I have had issues with asmlib in other places all relating to asm header corruption. None on any of my raw devices based asm installs.
>
> Just my 2 cents
>
>
>
>
> ----- Original Message -----
> From: Jeremy Schneider [mailto:jeremy.schneider_at_ardentperf.com]
> Sent: Tuesday, October 26, 2010 04:32 PM
> To: david.robillard_at_gmail.com <david.robillard_at_gmail.com>
> Cc: Michael Dinh <mdinh_at_xifin.com>; oracle-l mailing list <oracle-l_at_freelists.org>; John Thompson <jhthomp_at_gmail.com>
> Subject: Re: High Availability Options
>
> David Robillard wrote:
>> Should you decide to use ASM, I strongly suggest to stay away from ASMLib and use
>> udev instead.
>
> I'm a little curious about the reasoning for this.  I wrote a few blog
> posts (long ago) about uncertainty in the state of ASMLib... but these
> days I'm not so convinced anymore that it's worth avoiding.  UDEV is
> kinda nice if you understand it... but the documentation is poor and
> frankly I've met precious few who do understand it.  I tend to tell most
> people now to just use ASMLib unless they already know UDEV.  I'm
> skeptical that it's worth the time required to learn it.
>
> -Jeremy
>
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> Jeremy Schneider
> Chicago
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-- 
Yury
Oracle Certified Master
Mobile number: +61 414252591
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Received on Wed Oct 27 2010 - 04:54:30 CDT

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