Alternative/options for redundancy without vSAN

[vitaprimo]

Hi !

I've been studying up on the storage technologies from VMware, and I'm curious is to know if I could have something like vSAN, with data on more than one ESXi host. I'd like to know if there's a way of skipping the iSCSI/NFS datastore and hold the files in --usuallly-- faster internal drives but without needing to fill the stricter needs of vSAN.

I'm no so much interest in HA as much as in backup, I stumbled upon  vSphere Data Protection and vSphere Replication and both sound awesome but information is not quite clear, for instance, on vSphere Replication, does it work from site to site/cluster to cluster or can it be use intracluster as a lighter version or vSAN? VMware is master of adding ridiculously complicated language on ironically "software to greatly simplify" your lives -- I just watched a couple of keynotes.    Anyway...when I'm trying to absorb it I lose focus quickly just trying to figure things out myself.  

[cyberpaul · Accepted solution]

Hi vitaprimo,

it is a complex topic, but I'll try to point you the right direction. In short:

With VSAN you indeed can make your data reside on multiple hosts and utilize hosts' local drives. There are policies to set the number of copies of your data and therefore the number of host failures to tolerate.

This is not backup though, as every single write operation is synced to the other hosts immediately. Basically, you get a synchronous replica of your data. If you delete something by accident, you lose the replica as well.

VSAN aims to replace traditional centralized storage.

With vSphere Replication you get an asynchronous replica with RPO no less than 15 minutes. In case you loose the primary VM, you can boot up the replica and start using that, but you'll lose some most recent data. vSphere Replication can help you build a secondary site (also called a disaster recovery site).

vSphere Data Protection is a backup application. It stores multiple copies of your VMs in a compressed format. It is going to be replaced by more expensive EMC Avamar soon, so there is no point in deploying it imho.

If I understand your problem correctly, you might want to utilize VSAN (or an alternative solution like Starwind VSAN) to replace a traditional SAN array and to ensure HA / vMotion. Then you definitely should deploy a proper backup solution like Veeam or VMcom Backup to create periodical backups of your VMs.

Regards, Pavel

[TheBobkin]

Hello Pavel,

"with RPO no less than 15 minutes."

Actually minimum RPO for vSphere Replication with vSAN is 5 minutes:

How the 5 Minute Recovery Point Objective Works

Bob

[vitaprimo]

Thank you,

Yes, this is exactly what I was looking for. The central storage is itself backup and RAIDed but it starts to get slow with more VMs coming online and Iw as afraid of moving VMs off of the central storage where they'd be by their own. I'll try to setup multiple copies of VMs locally and use central storage for backup only.

Thanks again!

[cyberpaul]

Hi Bob, I was not aware of that, thanks!