Compute Disaster Recovery, Shared Storage & the Kitchen Sink [closed]

asked 2013-07-30 12:22:32 -0500

skyrainman gravatar image


I'm in the process of designing Openstack compute storage and trying to determine the best possible solution for disaster recover.

In short, if VM storage is local, in a disaster recovery scenario, one would have to restore the VMs from backup to a new host and start them there. Problem with this method:

  1. it takes longer to recover as the VM has to be copied
  2. the backup will likely be from a point in time, rather than latest
  3. Adds a layer of complexity to automation

On the other hand, the biggest problem I see with shared is performance as you're mounting over the network. Nothing shared beats the performance of local. Therefore, I'm my goal is to use the local disk, however, eliminating the disadvantages.

With that stated, has anyone found a better solution to use local storage, however, implement disaster recover eliminating the disadvantages above?

I have a few different cases I'm considering and would like any feedback:

  1. Basically, I come to find that Openstack stores the base image in /var/lib/nova/instances/_base, and everything else in the instances directory. I was thinking of a way to possible keep the _base directory local, while putting the instance data on a shared file system. This would decrease my network traffic greatly as the base image would reside on the local file system. However, I haven't found a way to tell Openstack to use a different directory for the _base directory.
  2. If I create a VM with a tiny instance, basically 0 disk space, is there a way to tell openstack to write all changes to the VM to the attached volume?

My goal in both cases is to keep the _base directory local, yet move the instance directory to a shared file system.

Also, if anyone has any experience with backing up Openstack VMs that would be great. Ideally, I am looking for a solution whereby it replicates in real time, so if I have to restore, I can restore the latest version. Veeam has the best solution for backing up VMs on the market which is really great, but it doesn't support Openstack.

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Closed for the following reason too subjective and argumentative by smaffulli
close date 2013-07-31 12:07:00.569784


This is not really a question as in 'a question that can have a short answer' but more a topic for a larger discussion. Please use one of the mailing lists and reserve this site for short questions around specific problems.

smaffulli gravatar imagesmaffulli ( 2013-07-31 12:06:48 -0500 )edit