6 Second Replication...

[jbarrow.viracoribt]

Our management is getting hit up by Zerto (www.zerto.com) to replace Veeam with their solution, touting "6 second replication." Speeds. Usually when things sound too good to be true, they are. Anyone familiar with how this stacks up to the Veeam application?

[Gostev]

Usually when things sound too good to be true, they are.

You are absolutely right on that. What they are not saying is that 6 seconds will be crash-consistent (virtual disk state of replica VM will be the same as if the server crashed at the time of replication). This means any data that was not committed to disks will be completely lost, plus application may have issues starting up when the replica is booted.

Veeam makes application-consistent and application-aware replicas (the latter means that application-specific backup and restore steps are performed, in additional to simple quiescence with VSS). Preparing the consistent VM image takes times, so you are looking at replication cycle taking a minimum of just under 60 seconds. This time requirement comes down to the VSS activities (VSS writers need time to quiesce their corresponding applications, prepare them for hot backup and flush any memory buffers to disk to avoid any data loss).

If you are seriously looking at crash-consistent replication for whatever reason, I recommend storage-based replication, which is normally synchronous or at least near-synchronous (but still times better than 6 seconds), and is fully supported by VMware. Zerto is not supported by VMware because VMware will not certify the way Zerto is retrieving virtual disk data from the hypervisor.

[zfs]

Hi Gostev
I must say that your response to jbarrow.viracoribt is not a very good one.
First of all Zerto can do application crash consistent replication just like Veeam, but without doing any snapshots, the difference is that this can not be done with the low RPO. The reason for this is that Zerto need to invoke the Zerto VSS provider in case of windows. Also it shall be noted that Zerto does not rely on VMware snapshots it does instead rely on journaling + recovery points. Zerto recovery pointes are more frequent than Veeam does its VMware snapshots. Though it shall be stated that I don't consider Zerto to be a competitor to Veeam (at the moment), for the simple reason that Zerto does not cover backup/restore, it only covers disaster recovery and it does it darn well with minimal loss of data (probably best in the market).

[zfs]

And hello again
Regarding the "Zerto is not supported by VMware"
I would say that this probably doesn't matter. The reason for this is that Zerto doesn't do any snapshots etc with the virtual machine. It only listens to the io and copies it. Which in my opinion is a good thing, and this is actually what a backup software should do as well. Using snapshot technology in VMware involves writes for the data you are backing up which in my opinion a backup software should not do.

[Gostev]

First of all Zerto can do application crash consistent replication just like Veeam ... the difference is that this can not be done with the low RPO

Perhaps you did not read Jonathan's question and/or my response carefully, because this is exactly what I said myself:

What they are not saying is that 6 seconds will be crash-consistent

Also, I never said they cannot do application consistent, which is something beginning of your response implies.

Regarding supportability - while I can appreciate that supportability by VMware "probably doesn't matter" for you, but it certainly is important for many customers that VMware supports them in case of VM and hosts issues, instead of them being on their own with Zerto troubleshooting misbehaving vSphere. And it's only fair to put all considerations out there for consideration, not just those important to some.

[zfs]

You are absolutely right, I actually did not read the crash consistent part carefully enough. I do apologize for that. Eitherway the replication is not done by snapshotting so the RPO in most instances will be much lower than with Veeam or storage replication. But in my opinion Veeam and Zerto should not be compared for the simple reason 1. Zerto is only a DR solution with the possibility to do restore (really hard). 2. Veeam is primarily a backup solution with DR.

[dellock6]

I beg to differ (I know, I work for Veeam...).
Veeam is at the same time a backup and replication solution, the difference is we use snapshot technology, Zerto uses IO stream splitting. Then we can discuss for hours which is the best method, pros and cons of each, but IO stream split is not the only way to do replication.

[zfs]

True you work for Veeam and this happends to be a Veeam forum . The key thing is more that I see Veeam as a complimentary product to Zerto or Zerto is a complimentary product to Veeam, while I think you see it more as a competitor, and I do understand why . The final point is that if you need really low RPO then I actually don't think there is any option to Zerto. Ok maybe EMC recovery point but this require kind of massive hardware investment. Well time to read your blog for weekend leisure.

[chrisdearden]

of course when products based on the new IO filtering APi come out, it should open the market up a little more ( recoverpoint VE will be the first to use it I believe.)