SAS cable hot plugable?

[IT_SedaNA]

Hello:

Storage/SAN newbie here, so this is likely easy for you experts.

Are the SAS cables hotpluggable on an MSA 2060? Can I simply plug in cable that's been removed? What is the impact of that?

I inherited an MSA 2060 with two storage controllers that connect to two ESXi hosts (ProLiant DL360 Gen10) via external SAS cables.

One of the two cables from controller A (?) is uplugged from the SAS port on one of the ESXi hosts.

I also noted that both management controllers are not accessible via GUI or SSH.

So far, no errors reported and all VMs seem to run OK.

Appreciate any advice as I do not want to bring down a production system. Thank you.

[JonPaul]

@IT_SedaNA 
yes SAS cables are hot-pluggable.   You should probably do some due-diligence on why the cable was removed before plugging it back in.
When the cable is plugged in, the HBA ans the MSA will start communicating and the MSA will present any LUNs that are explicitly mapped to the HBA and the host OS.  In most cases this is a good thing an adds to the redundancy of the system if the host OS is configured correctly.  If there is a configuration problem on the host then the additional LUN presentation could be seen as a new and different LUN and cause confusion to the OS.
I think your first step is to get access to the MSA management.  Using the Mini-USB cable would be an easy option if you are onsite.  If not then it could be a routing problem or MSA IP problem (see MSA FW release notes, search for '157')
Some good websites to have:
MSA Firmware:  https://www.hpe.com/storage/MSAFirmware
MSA HealthCheck:  https://www.hpe.com/storage/MSAHealthCheck

Now one 'silly' question back:  You have a SAS host protocol MSA 2060,  you are not using the expansion port (goes to expansion MSA Disk Enclosures) to connect your host, right?

[IT_SedaNA]

Hi JonPaul:

Thanks for the reply. Yes, the million dollar question is how the cable became detached.

So, if I understand you correctly, re-attaching the cable should have no negative impact. Is that correct?

As for re-attaching the cable . . . Yes, I can connect to the MSA w/ a USB cable and should be able to login. From there, should I re-start the managment contollers? Both are down (no https/SSH access). Once mgmt. controllers are up, should I then re-attach the cable so I can observe the results?

In the meantime, yes, both cable paths were defined in ESXi . No expansion port as best I can tell. The only connection is from each onboard card/port to each ESXi host. It's a pretty simple desigin: We have two hosts backed by the MSA) for redundancy.

Thanks again for the assist. This is all rather new to me and I don't want to make a bigger mess.

[Cali]

Use Serial over USB: Serial: 115200,8,N,1,N

Check Network with: show network-parameters

Check System with: show configuration

Restart Management with: restart mc a (b)

Cali

[IT_SedaNA]

Hi @Cali :

Thanks for the info. No joy however. I get the following error:

Unable to login. This interface is not enabled for this user

The password on file should be OK. I got a bad password message when intentionally mis-typing the password. Tried w/ PuTTY and Teraterm on both controllers. I'm assuming a full reboot is the next step?

All the best,

Patrick

[Mr_Techie]

@IT_SedaNA 

It sounds like the management interfaces may be in a state where the credentials are being recognized but access is blocked due to either a configuration issue or a state where the management controllers aren't functioning properly. Firstly I would say confirm the user access. If possible, try logging in with a different user account (e.g., a default "admin" account) to see if the issue is isolated to your user credentials. Then you are try to rebooting the management controllers. 

Hope this helps.