Re: [DISCUSS]Migration of NFS Secondary Storage to Object Store

[Min Chen <mi...@citrix.com>]

Hi Manasa,
Please see my comments in line.

Thanks
-min

From: "Manasa Veloori (3P)" <ma...@citrix.com>>
Date: Thursday, November 7, 2013 3:41 AM
To: "dev@cloudstack.apache.org<ma...@cloudstack.apache.org>" <de...@cloudstack.apache.org>>
Cc: Min Chen <mi...@citrix.com>>
Subject: [DISCUSS]Migration of NFS Secondary Storage to Object Store

Hi,

I Have gone through the FS https://cwiki.apache.org/confluence/display/CLOUDSTACK/Migration+of+NFS+Secondary+Storage+to+Object+Store .

Below are my review comments:

In Migration steps:
Step2:
We also automatically increment reference count of these old templates, volumes and snapshots on old NFS so that they cannot be recycled during our scheduled cache store cleanup thread. Their reference count will be decremented when we really migrate the content to S3.------In what scenarios does the  old templates/volumes/snapshots  get  migrated to the new S3.

[Min] As mentioned in Step 4 and Step 5, old templates will be migrated to new S3 when you invoked copyTemplate or extractTemplate. Old volumes will be migrated to new S3 when you invoke extractVolume.

Step3: For each new snapshot taken after migration, we will always take a full snapshot to newly added S3, so there will no issues to coalesce delta snapshots cross NFS and S3 stores.--------for the new snapshots ,full snapshot will be taken. Will the reference count of the delta snapshots which are already present in the NFS incremented. If that is the case then they will never get deleted from NFS cache as a part of cache store clean up.

[Min]  Yes, the reference count of the old delta snapshots present in NFS will also be incremented. In case that customer still wants to restore back the old snapshots and they can still do that.

At step5 : For volume, we will trigger copy of the template to the new S3 object store when user invokes ExtractVolume.— “it should be trigger copy of volume(not template) to new S3”

[Min] Fixed in FS.

Thanks,
Manasa