topic Re: MSA 2040 LUNs Response configuration in MSA Storage

MSA 2040 LUNs Response configuration

m85m — Tue, 11 Apr 2017 07:22:13 GMT

Hi,

I have a MSA 2040 already configured. I came accross some best practices for MSA2040 and Vsphere that I should have read earlier. Luckily for me there is not much that I have missed but for this:

If the system is used in a VMware environment, set the system Missing LUN Response option to use its Illegal Request setting. To do so, see either the configuration topic “Changing the missing LUN response”

In the same best practice's document it explains how to do it before creating the LUNS. My question is, can I modify that setting after having all my volumes created?

PS: I'm referring to this document: https://www.hpe.com/h20195/v2/getpdf.aspx/4aa4-7060enw.pdf

Thanks!

Re: MSA 2040 LUNs Response configuration

AnkitM — Thu, 18 Jun 2015 01:43:03 GMT

Yes, you can but not required if you are not facing any issue.

Detailed Information:

Some operating systems do not look beyond LUN 0 if they do not find a LUN 0 or cannot handle noncontiguous
LUNs. The Missing LUN Response option handles these situations by enabling the host drivers to continue probing for
LUNs until they reach the LUN to which they have access.
This option controls the SCSI sense data returned for volumes that are not accessible because they don’t exist or have
been hidden through volume mapping (this does not apply to volumes of offline vdisks). Use the default value, Not
Ready, unless the system is used in a VMware environment or a service technician asks you to change it to work
around a host driver problem.

To change the missing LUN response
1. In the Configuration View panel, right-click the system and select Configuration > Advanced Settings > Cache.
2. Set the Missing LUN Response option to either:
• Not Ready. Sends a reply that there is a LUN where a gap has been created but that it’s “not ready.” Sense
data returned is a Sense Key of 2h and an ASC/ASCQ of 04/03. This option is the default.
• Illegal Request. Sends a reply that there is a LUN but that the request is “illegal.” Sense data returned is a
Sense Key of 5h and an ASC/ASCQ of 25/00. If the system is used in a VMware environment, use this
option.
3. Click Apply.

Reference: http://h20564.www2.hp.com/hpsc/doc/public/display?docId=emr_na-c03792054 Page Number 144.

Re: MSA 2040 LUNs Response configuration

m85m — Thu, 18 Jun 2015 06:36:49 GMT

Thanks! That was really helpful. I wasn't having any issue as my LUN's have consecutive numbering, so I will not modify it.

Re: MSA 2040 LUNs Response configuration

kennygno — Fri, 01 Jul 2016 06:15:30 GMT

This is a bit confusing.

Since m85m found this in a best practive document for vSphere I assume that it is used in a VMware environment.

In the answer from AnkitM "not required if you are not facing any issue. .... Use the default value, Not Ready, unless the system is used in a VMware environment".

So if I'm in a VMware environment and don't have any issue. Should I still do it? And can I do this on an already productiv running system?

Because in the document they mention that this setting needs to be done before creating volumes/LUNs.