Hello, 

> De: "Paco Orozco" <[email protected]>
> À: [email protected]
> Envoyé: Mardi 23 Octobre 2012 08:22:29
> Objet: Re: backup a cloudstack deployment

> Hi Julien,

> Good point! We have a private IaaS cloud and we have the same
> question.
> At the beginning documentation and forums recommends to backup MySQL
> DB
> and the secondary storage.

> I'm using Cloudstack and Xen servers with LVM as a primary storage.
I'm using KVM along with Cloudstack with iSCSI and GFS2 (on Dell Equallogic) as 
primary storage. 
As secondary storage, I am thinking at using disk based backup appliance with 
inline deduplication (Quantum, EMC DataDomain, ...), has anyone tried such a 
setup ? Are performances good enough or do I need some kind of speedy NFS 
server ? 

> I'm doing it but I've got some not solved questions.

> 1) Geoff says "You should have every VM running a Scheduled Snapshot
> routine, that way if you have a disaster, you can recreate your
> architecture, and restore VMs from Snapshots / Templates". When you
> schedule this snapshot routine it will create snaps on secondary
> storage. Does this snaps count as a consumed resources for users?
> Must
> they will pay for it? Can users delete them?
As far as I know, a snapshot is a resource as others, it has its own limits, 
different from the volumes. Users can delete their own snapshots. The service 
offer we are planning to provide is to tell users they have all the tools to 
plan their own backup (via the snapshots) and are responsible to set it up for 
their VMs. We ensure that in case of disaster on primary storage, they will 
have tools to recover failed VMs. 

I've done some testing around snapshots (manual or scheduled) and it appears 
that, vm running or not, I have a lot of errors. For example, I've scheduled 
hourly snapshots on a VM, keeping the last 3, and I currently have : the last 
backup is in error, the two others are OK on the root disk, and for the data 
disk only the last is good. 

Does anyone face this kind of snapshots problems ? 
Another question around that, are there means to have a copy of a volume on 
secondary storage or only snapshots are stored on it ? 

> 2) I'm now testing a solution for PHD in order to do VM backups from
> Xen
> Server. Are you using Xen or KVM/VMware?
I did not look for kvm specific backup solutions, I have a little background 
with XenServer and last time I looked at it, I finished with a perl script that 
did vm snapshoting before moving the volume to a dedup appliance (Quantum DXi) 
> 3) I need to protect myself from harware failures (mirroring) and
> software or human errors (backup). Are you only using mirror?
For human errors, in Cloudstack, I think that the cleanup delay before removing 
destroyed VMs can help a lot. I'm also quite afraid of data corruption on the 
raid array, e.g. many disks failing at the same time because of a bad series... 
How long will it take to recover the whole platform if only from secondary 
storage ? And recover will only be on the user behalf ? 

How will Cloudstack behave if a lot of VMs on a primary storage are not 
available ? 

> Thanks
> --
> Paco Orozco ([email protected])
> SIP: [email protected]
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