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DRV_CFG Remove MDM
Is there a command to remove an MDM within the windows SDC? There is one to add one and modify the IP's of one, but I don't see anything related to removing an MDM from the config.
echolaughmk
522 Posts
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July 22nd, 2016 09:00
So what I did in testing it was add an MDM (MDM1) when the SDC was setup. But I didn't give it the range of IP's when adding the first MDM. So then I added the second MDM with the --add_mdm option and now I have 2 MDMs. I then modified the first MDM entry to have both IP's of MDM1/MDM2 with the --modify_mdm_ip command (which is what I should have done from the start).
Now I have 2 MDM's that show up and when I reboot the primary MDM, what I am seeing on the Windows box is double the number of targets and volumes.....but the second volume is really a ghost volume of the first one in use....as if ScaleIO can't interrogate it and I am thinking it is due to the way the MDM's were added since the --add_mdm is really intended for a second cluster it seems.
I just uninstalled the SDC and will set it up correctly from scratch and then test to see if I get the same result. But I thought it was odd that there is an --add_mdm (which creates a new entry line in the config/kernel), but nothing to remove it...
thanks!
pawelw1
306 Posts
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July 22nd, 2016 09:00
Hi Keith,
Can you simply try to replace the MDM IP address with the one of your choice? I don't see why you would want to remove it completely, without MDM SDC doesn't know what to do so there should always be one configured.
Thanks!
Pawel
pawelw1
306 Posts
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July 22nd, 2016 13:00
Hi,
I actually never tried it, but from what I see in the documentation, it says "This command is typically used in cases where an SDC is connected to more than one ScaleIO systems" - so it looks like you add a cluster (MDM) with --add_mdm and then you can modify the IP addresses for this cluster to add/remove MDMs - and if you run it again, it will connect to another system - guess that's your "ghost" volume.
Interesting :-)
Cheers,
Pawel
echolaughmk
522 Posts
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July 25th, 2016 07:00
yeah, not sure. I tried to "zero-out" the MDM's IP's for the one I added but it didn't take. Seems odd there is no "remove" command still though. Like if you added one from a disconnection and then wanted to change/migrate to new on down the line.
The other test was to initially add the primary MDM with the --add_mdm and then add the secondary MDM also with the --add_mdm (versus the --modify_mdm_ip). That produced the same weirdness in the outputs since the config wasn't able to interrogate the MDMs to realize they were part of the same cluster. I was just doing some of these test since the document is poorly written on the CLI side of things and going through motions that customers might do and then need some reconfiguration due to best practices. Is there a best practices for Windows being written possibly or a in-depth CLI guide perhaps?
Thanks Pawel!
pawelw1
306 Posts
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July 26th, 2016 04:00
Hi Keith,
I am not aware of any more in-depth CLI guide than the User Guide, I am sorry. I will try to ask around and let you know.
I don't have any Windows host in the lab, but can you try to search for SDC configuration in the Windows Registry and remove MDM IPs from there? I did similar on my Linux SDC and removed it from drv_cfg.txt file - then drv_cfg --query_mdms returned 0 - I guess that might be a workaround?
Please don't treat it as official EMC recommendation, rather a lab exercise ;-)
Cheers,
Pawel
echolaughmk
522 Posts
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July 27th, 2016 09:00
haha...no problem..this is a test environment for the most part anyways. I didn't think about the registry so I will give that a try...thanks for all the help!
I ended up fixing it by uninstalling the SDC and re-installing and then giving it both MDM IP's on the initial command for now, but I am intrigued by your thoughts so will try that out when I get a moment.
thanks!
-Keith
pawelw1
306 Posts
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July 27th, 2016 12:00
Sure - let me know how did it go, it's interesting!