[dm-devel] [PATCH v3] libmultipath: update INFINIDAT builtin config

[Martin Wilck]

Xose,

On Wed, 2018-12-12 at 17:58 +0100, Xose Vazquez Perez wrote:
> On 11/7/18 11:41 AM, Martin Wilck wrote:
> 
> > I apologize for coming back to this after more than a year.
> > I've been wondering about your dev_loss recommendation.
> > 
> > What is the rationale for setting dev_loss and fast_io_fail to the
> > same
> > value, which is straight against the general recommendation? And
> > what
> > is the reason for the aggressively low dev_loss value anyway?
> > Device
> > loss and re-discovery is much more complex to handle for both the
> > kernel and multipathd than failure/reinstantiation. You are the
> > only
> > vendor who recommends setting dev_loss less than the default of
> > 600s. 
> > 
> > Could you share your reasoning please?
> IMO, any change of a standard value should be documented.

I agree. Have you looked at the past conversation (August 2017)? You
challenged Arnon for explanations, but he came up with just a general
statement ("Timeout and path recovery values are adjusted for error-
free hot upgrade scenarios."), no detailed explanations. In particular,
no rationale was given for the unusually aggressive dev_loss setting.
That's the point of my inquiry.

Martin

-- 
Dr. Martin Wilck <mwilck at suse.com>, Tel. +49 (0)911 74053 2107
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton
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