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From: Hannes Reinecke <hare@suse.de>
To: Christophe Varoqui <christophe.varoqui@opensvc.com>,
	device-mapper development <dm-devel@redhat.com>
Subject: Re: ALUA - rescan device capacity on zero sized block devices
Date: Mon, 20 Apr 2015 07:58:24 +0200	[thread overview]
Message-ID: <55349580.1040205@suse.de> (raw)
In-Reply-To: <CABr-GnefEhc_dOKs360Hox7asbvO5qN8BqPczqC+V8CQ6Myh8w@mail.gmail.com>

On 04/19/2015 12:56 AM, Christophe Varoqui wrote:
> About five years ago, we faced a somewhat simular issue with
> Symmetrix arrays, where the replicated LU of a SRDF pair (R2) was
> flagged read-only by the kernel upon discovery. Splitting the pair
> with a symcli command  made the LU read-write from the array
> controller point of view, but the Linux kernel would not promote it
> read-write dynamically.
> 
> I don't know if the Symmetrix array also use a unit attention to
> signal the change to the initiators. If it does, it might be worth
> trying to address both the 3par peer persistance and the Symmetrix
> SRDF situations.
> 
> On the other hand, if the SRDF R2 rw promotion issue has been fixed
> since, the patch might give guidance about where/how to plug the
> 3par peer persistance ghost path rescans.
> 
It's not only that; if you are faced with LUNs in standby even the
kernel wouldn't detect them properly.

I'm currently debugging this issue and will have an update soon(-ish).

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		               zSeries & Storage
hare@suse.de			               +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)

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  reply	other threads:[~2015-04-20  5:58 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-13 15:32 ALUA - rescan device capacity on zero sized block devices Thomas Wouters
2015-04-13 17:44 ` Bart Van Assche
2015-04-14  7:20   ` Thomas Wouters
2015-04-14  7:45     ` Bart Van Assche
2015-04-14 14:34       ` Christophe Varoqui
2015-04-14  8:14     ` Hannes Reinecke
2015-04-14  9:49       ` Bart Van Assche
2015-04-18 22:56         ` Christophe Varoqui
2015-04-20  5:58           ` Hannes Reinecke [this message]
2015-06-10 15:02             ` [dm-devel] " Ewan Milne
2015-06-11  5:52               ` Hannes Reinecke
2015-06-12 15:17                 ` Ewan Milne
2015-06-12 16:59                   ` Ewan Milne

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