Hi Tony,

 

It looks like Cheesecake didn’t survive but apparently some components of it did; details in https://docs.openstack.org/cinder/pike/contributor/replication.html

 

I’m not using Cinder now; we used it at eBay with Ceph and Netapp backends. Netapp makes it easy but is expensive; Ceph is free but you have to figure out how to make it work. You’re right about forking; we did it and then upgrading turned from an incredibly difficult ordeal to an impossible one. It’s better to stay with the “official” code so that upgrading remains an option.

 

I’m just an operator; hopefully someone more expert will reply with more useful info.

 

It’s true that our community lacks participation. It’s very difficult for a new operator to start using openstack and get help with the issues that they encounter. So far this mailing list has been the best resource for me. IRC and Ask Openstack are mostly unattended. I try to help out in #openstack when I can, but I don’t know a lot so I mostly end up telling people to ask on the list. On IRC sometimes I find help by asking in other openstack-* channels. Sometimes people complain that I’m asking in a developer channel, but sometimes I get help. Persistence is the key. If I keep asking long enough in enough places, eventually someone will answer. If all else fails, I open a bug.

 

Good luck and welcome to the Openstack community!

 

From: Tony Pearce <tony.pearce@cinglevue.com>
Sent: Wednesday, January 15, 2020 11:37 PM
To: openstack-discuss@lists.openstack.org
Subject: DR options with openstack

 

Hi all

 

My questions are;

 

  1. How are people using iSCSI Cinder storage with Openstack to-date?  For example a Nimble Storage array backend. I mean to say, are people using backend integration drivers for other hardware (like netapp)? Or are they using backend iscsi for example?
  2. How are people managing DR with Openstack in terms of backend storage replication to another array in another location and continuing to use Openstack?

 

The environment which I am currently using;

1 x Nimble Storage array (iSCSI) with nimble.py Cinder driver

1 x virtualised Controller node

2 x physical compute nodes

This is Openstack Pike.

 

In addition, I have a 2nd Nimble Storage array in another location.

 

To explain the questions I’d like to put forward my thoughts for question 2 first:

For point 2 above, I have been searching for a way to utilise replicated volumes on the 2nd array from Openstack with existing instances. For example, if site 1 goes down how would I bring up openstack in the 2nd location and boot up the instances where their volumes are stored on the 2nd array. I found a proposal for something called “cheesecake” ref: https://specs.openstack.org/openstack/cinder-specs/specs/rocky/cheesecake-promote-backend.html
But I could not find if it had been approved or implemented. So I return to square 1. I have some thoughts about failing over the controller VM and compute node but I don’t think there’s any need to go into here because of the above blocker and for brevity anyway.

 

The nimble.py driver which I am using came with Openstack Pike and it appears Nimble / HPE are not maintaining it any longer. I saw a commit to remove nimble.py in Openstack Train release. The driver uses the REST API to perform actions on the array. Such as creating a volume, downloading the image, mounting the volume to the instance, snapshots, clones etc. This is great for me because to date I have around 10TB of openstack storage data allocated and the Nimble array shows the amount of data being consumed is <900GB. This is due to the compression and zero-byte snapshots and clones.

 

So coming back to question 2 – is it possible? Can you drop me some keywords that I can search for such as an Openstack component like Cheesecake? I think basically what I am looking for is a supported way of telling Openstack that the instance volumes are now located at the new / second array. This means a new cinder backend. Example, new iqn, IP address, volume serial number.  I think I could probably hack the cinder db but I really want to avoid that.

 

So failing the above, it brings me to the question 1 I asked before. How are people using Cinder volumes? May be I am going about this the wrong way and need to take a few steps backwards to go forwards? I need storage to be able to deploy instances onto. Snapshots and clones are desired. At the moment these operations take less time than the horizon dashboard takes to load because of the waiting API responses.

 

When searching for information about the above as an end-user / consumer I get a bit concerned. Is it right that Openstack usage is dropping? There’s no web forum to post questions. The chatroom on freenode is filled with ~300 ghosts. Ask Openstack questions go without response. Earlier this week (before I found this mail list) I had to use facebook to report that the Openstack.org website had been hacked. Basically it seems that if you’re a developer that can write code then you’re in but that’s it. I have never been a coder and so I am somewhat stuck.

 

Thanks in advance

 

Sent from Mail for Windows 10