Backup, Replica or both?

[1-0-1]

Is there any real big differences between backup vs replication over WAN? I find that backup are more flexible to work with providing there is a VEEAM server on the remote site when not using pull based replication/backup. This can be solved by running a separate replication job for the VEEAM server (providing it is a virtual guest) at least once a week to the remote location.

Biggest drawback for me is that replicas only has a limited number of historical replicas I can keep.

[Gostev]

The top 3 biggest differences are recovery time, disk space required, and amount of restore points supported.

[mckenzieaj]

I appreciate there are already many threads on the whole backup Vs Replication. This is the lucky one to get my question as addendum in these most excellent forums!

In each case the answer to the "backup vs replication" is about overheads vs RTO's and I am fine with that. The amount of restore points mentioned above is something I had not read yet (can you give me a pointer to that bit of the docs?). In the scenario I am currently working with I had thought to use replicas for short term backup history (critical VMs) for a good RTO, overlaid with backups for a much longer, less regular ( and efficient) backup history (all VM's)

However, when I started testing the AIR wizard to do an exchange mailbox item restore out of a replica, I realised something... If you replicate, you cannot use the AIR wizard to do granular object restores of MS Exchange, SQL etc. These only work for backup jobs. For replicas you only really have the option of a file based restore.

If that is the case then isn't that also a decision point if deciding backups vs replicas, or am I missing something here?

I wanted to reference a post where gostev said something like: "The only difference between a backup and a replica is where and how it is stored" but could not find it, so not sure if I am remembering the statment incorrectly out of context. My view is "How you recover" is always an important part of the conversation as well!

Thanks
Andrew McKenzie

[Gostev]

Hi Andrew, no - this is not a decision point, since you never just replicate (this is insufficient protection). Typically, you backup ALL of your VMs, and in addition to that, most critical VMs you also replicate for a good RTO.

Backups are stored on regular storage and in the compressed/deduped format, while replicas are stored on VMFS storage and in native format (uncompressed), so replicas take lots more disk space.

Thanks.

[mckenzieaj]

Thanks Gostev.

This is a key statement for me: "since you never just replicate (this is insufficient protection)". Is this because of what I discussed in my post, I.E. your granular restore options for things like Exchange etc are not as good, or are there other rationales as well?

Up until reading your reply I had thought that a replica, while not offering as much flexibility on the restore front, was as good a "backup" as a vm backed up via a backup job.

Thanks
Andrew

P.S. Upgrade to version 6 was insanely easy... nice work.

[Gostev]

Hi Andrew, primary reason why replica is insufficient protection, is that backup is not considered a backup until you have 3 copies of it. I elaborate more on this here. Of course, keeping 3 uncompressed copies of replica is hard to achieve (it means you have to replicate to 3 different VMFS datastore).

Other reason is that most companies have requirement to keep many more restore point than a replica allows (28 restore points with v6), with 60 or 90 being most typical retention of data on disk (for quick "operational" restores). Additionally, most companies have long term retention requirements (such as keeping monthly full backups for archival purposes for years on tapes or external storage - again, coming back to the fact that replica is uncompressed, this would be hard to do.

Thanks for your kind words on v6.

[webstyler]

[merged]

Hello

Settings for any customer VM replica

So my question is what may be sense of made also backup ?

And, may be good idea backup the VM replicated but lower point of restore ?

Thanks for any help / suggest

WS

[foggy]

Simon, backups are commonly used for archival purposes as they are much more disk space efficient (compressed and deduped). Moreover, they allow to store much more restore points than replicas do. Replicas are used for quick restore to the latest state mostly. So it's all about your requirements to backup&recover strategy and retention policy. Thanks.

[Gostev]

Merged since this thread has good discussion of backup vs. replication, please review the above.

[Reimold]

[merged]

Hello,

i was not able to find an existing topic to my question, so i am sorry if the matter is allready discussed. We have a running Veeam B&R enviroment and backing up our servers from the Equallogic-San to an windows-repository with local disks and it is running fine so far.

Now we are going to install new hardware in one of our subsidiaries i have the following scenario: 4 virtual servers (together around 2 TB) running on one host connected to a small Equallogic-San and for Backup i have another host connected to the San with additional 15 TB of local disks. Now the question comes to me if it is better to replicate the servers from the producitve host to the second ones local disks or do a backup to a repository vm running on the second server.

Where are the advantages/disadvantages from doing replication instead of backup. On thing i think of, is that the repository vm used for backup can only have 2TB disks because of the vSphere limits.

br

Dirk

[Vitaliy S.]

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