Questions about agent-less backup

Question

Hello, 
 I am trying to decide if I should go with agent or agent-less and I've run into several questions that my searching has not been able to answer so I thought I would post here and see if I could get the info all in one place. 
 Environment is vmware with 8 vm's, a combination of Active Directory and Exchange servers on Win 2008 R2 and 2012 R2 running on esxi 5.5 free. 
 The goal is to use continuous virtual standby hourly. In the event of hardware failure the standby can be turned on with the loss of only an hour. As well the standby can be copied offsite for DR. 
 First question is about licensing. From what I've read I can backup all 8 vm's with 1 license if I use agent-less. If I choose to install the agent on each machine will it recognize this is a single vmware server and need just one license or do I have to pay for all eight licenses? 
 This machine is running esxi 5.5 and is the free version. Will we need to buy (at least) essentials for rapid recovery to back it up agent-less? 
 The main purpose of protecting this machine is to do continuous virtual standby for the AD and Exchange servers. I have read that agent-less backup does not read Exchange/SQL meta data. So does that mean I won't be able to do continuous virtual standby or just that I could not use these backups to restore individual databases, mailboxes, email items etc? 
 These are very small Exchange servers (maybe 15 users each) so hourly backups with continuous virtual standby is a ridiculously easy and cheap way to completely restore these machines in minutes back to an hour ago. If I can do this with agent-less for one license that would be amazing. I can even take copies of them offsite for DR. 
 Ideally having the ability to restore mail items, databases would be great too but I can live without that in this case. But speaking of that, if the client is running some other agent on the guest's (for exchange item restores) would that affect rapid recovery in any way? I'm thinking it would not. 
 Any help with these questions is greatly appreciated 
 James

Tim Seymour · Answer

1. You can either buy agent licenses (so you pay per machine backed up) or you can buy a virtual license. If you buy the virtual license you will pay per number of CPU sockets in your VMware hosts. With either license you could protect the machines with an agent, as agentless, or a combination of the two. I recommend talking to your account rep to figure out which makes more financial sense for you. 
 
2. You cannot do agentless backup with ESXi free version. You also cannot do virtual export to ESXi free version. You will need at least essentials. Depending on what transport mode you want to use for backup ( pubs.vmware.com/.../index.jsp you may need a higher version. 
 
3. The Exchange and SQL metadata gathering allow you to do things like mountability/attachability checks as well as log truncation. Log truncation is usually the most important thing that you need from the backup software that you wouldn't get with agentless protection. So more than likley you are going to want to run an agent on your Exchange server in order to have access to log truncation. Metadata gathering has nothing to do with continuous virtual standby. As long as you are backing up the machine successfully (with agent or agentlessly) and it meets the requirements for virtual standby (no dynamic spanned volumes, etc.) then it will be able to be configured for virtual standby. If you wanted to do granular restore of Exchange mailboxes and you used agentless protection, this is still possible, you would just have to manually mount the recovery point of the Exchange server, then manually point the Mailbox Restore utility to the database and logs so that it could open them for recovery. 
 
4. If you are using agentless backup, then it doesn't matter what software is installed on the guest VM OS. We are using VMware APIs to backup the VM so it does not care what the OS is or what the OS is doing on the guest VM. 
 
I agree that your plan to do backups and virtual standby makes a lot of sense for recovery. You could also fairly easily add an offsite core either on your own hardware (included in your license) or to a cloud host like Azure, or to a 3rd party provider and get true offsite DR for a fairly small amount of money extra.

Tudor.Popescu · Answer

Hi James: 
Alas, agentless protection is a non-option for you at this time as you are using ESX 5.5 free. This VMWare ESXi version does not provide the vddk API functionality. You may upgrade to any paid licensed version of ESXi to protect VMs agentlessly. Your ability to restore e-mail items is not hindered under by agentless protection. To restore e-mails you need to be able to mount recovery points and connect to the e-mail databases and logs using the built-in Mail Recovery application. 
Licensing is rather complicated. The virtual license covers Host CPU Sockets. Agent licenses cover the number of protected agents. The choice depends of your environment. However, since the Agent licenses can be used both in virtual and physical environments, it seems to me to be the most flexible option.

Tim Seymour · Answer

Take 2 - pubs.vmware.com/.../index.jsp . 
 
Basically there are 3 transport methods - NBD, HotAdd, and San Transport. NBD runs all the traffic over your prod network. HotAdd works when the core is a VM and allows VMware to mount the VMDK that is being backed up as a local disk on the core VM taking the load off of the network. San Transport allows a physical core server to connect directly to the SAN on the storage network when taking a backup. The core will default to whichever one it can do, you just have to have the prerequisites configured and the proper ESXi version for each.