Veeam Backup & Replication leverages SMB Multichannel

Introduction

Is it true that Veeam Backup & Replication leverages SMB Multichannel? That is a question that I was asked recently. The answer is yes, when you have a backup design and configuration that allows for this. If that’s the case it will even happen automatically when possible. That’s how SMB 3 works. That means it’s a good idea to pay attention to the network design so that you’re not surprised by the route your backup traffic flows. Mind you that this could be a good surprise, but you might want to plan for it.

I’ll share a quick lab setup where SMB 3 Multichannel kicks in. Please don’t consider this a reference guide for your backup architectural design but as a demo of how SMB multichannel can be leveraged to your advantage.

Proving Veeam Backup & Replication leverages SMB Multichannel

Here’s a figure of a quick lab setup I threw together.

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There are a couple of significant things to note here when it comes to the automatic selection of the best possible network path.

SMB 3 Multichannel picks the best solution based on its logic. You can read more about that here. I’ve included the figure with the overview below.

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The figure nicely show the capabilities of the NIC situation. To select the best possible network path SMB 3 uses the following logic:

1. RDMA capable NICs (rNICs) are preferred and chosen first. rNICs combine the highest throughput, the lowest latency and bring CPU offloading. on the processor when pushing through large amounts of data.

2. RSS capable NICs: NIcs with Receive Side Scaling (RSS) improve scalability by not being limited to core zero on the server. Configured correctly RSS offers the second-best capabilities.

3. The speed of the NICs is the 3rd evaluation criteria: a 10 Gbps NIC offers way more throughput than a 1 Gbps NIC.

Following this logic it is clear that Multichannel will select our 2 RDMA capable 10Gbps NICs over the management LBFO interface which does not support RDMA and while supporting RSS can only deliver 2Gbps throughput at best. That’s exactly what you see in the screenshot below.

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Conclusion

So yes, Veeam Backup & Replication leverages SMB Multichannel! Please note that this did not require us to set SMB 3 Multichannel constraints or a preferred network for backups in Veeam Backup & Replication. It’s possible to do so when needed but ideally you design your solution to have no need for this and let automatic detection chose the best network path correctly. This is the case in our little lab setup. The backup traffic flows over 10.1.0.0/16 network even when our Veeam Backup & Replication VM, the Hyper-V host and the backup target have 10.10.0.0/16 as their management subnet. That’s the one they exist on the Active Directory domain they belong to for standard functionality. But as both the source and the target can be reached via 2*10Gbps RDMA capable NICs on the 10.1.0.0/16 subnet SMB3 will select those according to its selection criteria. No intervention needed.

SMB Direct Support

Now that we have shown that Veeam Backup & Replication backups in certain configurations can and will leverage SMB Multichannel to your benefit another question pops up. Can and does Veeam Backup & Replication leverage SMB Direct? The answer to that is also, yes. If SMB Direct is correctly configured on all the hosts and switches their networks paths in between it will. Multichannel is the mechanism used to detect SMB Direct capabilities, so if multichannel works and sees SMB Direct is possible it will leverage that. That’s why when SMB Direct or RDMA is enabled on your NICs it’s important that it is configured correctly throughout the entire network path used. Badly configured SMB Direct leads to very bad experiences.

Now think about that. High throughput, low latency and CPU offloading, minimizing the CPU impact on your Hyper-V hosts, SOFS nodes, S2D nodes and backup targets. Not bad at all, especially not since you’re probably already implementing SMB Direct in many of these deployments. It’s certainly something that could and should be considered when design solutions or optimizing existing ones.

More SMB3 and Windows Server 2016 Goodness

When you put your SMB3 file share continuously available on a Windows 2012 (R2) or Windows Server 2016 cluster (it doesn’t need to be on a CSV disk) you’ll gain high availability trough transparent failover with SMB3 and except for a short pause your backups will keep running even when the backup target node reboots or crashes after the File Server role has failed over. Now, start combing that with ReFSv3 in Windows Server 2016 and the Veeam Backup & Replication v9.5 support of this and you can see a lot of potential here to optimize many aspects of your backup design delivering effective and efficient solutions.

Things to investigate further

One question that pops up in my mind is what happens if we configure a preferred back-up network in Veeam Backup & Replication. Will this affect the operation of SMB multichannel at all? By that I means would enabling a preferred network in Veeam prevent multichannel from using more than one NIC?

I my opinion it should allow for multiple scenarios actually. When you have equally capable NICs that are on different subnets you might want to make sure it uses only one. After all, Veeam uses the subnet to configure a preferred path, or multiple subnets for that matter. Now multichannel will kick in with multiple equally capable NICs whether they are on the same subnet or not and if they are on the same subnet you might want them both to be leveraged even when setting a preferred path in Veeam. Remember that 1 IP / NIC is used to set up an SMB session and then it detects capabilities available, i.e. multiple paths, SMB Direct, RSS, speed, within 1 or across multiple subnets.

I’ll leave the combination of Veeam Backup & Replication and SMB multichannel for a future blog post.

I’m a Veeam Vanguard 2017

I’m a Veeam Vanguard 2017 I learned tonight

I came home tonight after a long day at work. The day was one of trying to solve some weird remote client issues, helping colleagues, supporting the devs, etc. There was also some fun whilst teaching some PowerShell skills to a colleague. It keeps them motivated and it also showed him future path were thing can and are going. Which reminds me of the good feeling being part of the Veeam Vanguard program gives me. Speaking of which …

What put a huge smile on my face tonight was an e-mail confirming I was invited to the  Veeam Vanguard program again in 2017. Excellent news! And yes I did accept. What did you think!?I’m a Veeam Vanguard 2017

Being a Veeam Vanguard

So yes, I’m a Veeam Vanguard 2017. The Veeam Vanguard program is to me is about sharing, learning and growing through interaction with some of the finest techies any company out there could ever hire. It is full of hard core, highly skilled and experienced technologists from around the globe. They range from intensively hands on types deep in the trenches to real architects & strategists.

These are people that elevate me, teach me, educate me and, every now and then, make me feel very humble due to the depth and breadth of their knowledge. While I have my strengths, I sometimes feel out of my league among them. But that’s OK. Not being the smartest guy in the room and group means I’m learning and advancing. It makes it interesting and the diversity in skills and technologies make for a better stronger group that can deal with wide variety of challenges.

Everybody contributes to help each other, customers and clients which is good for us, for everyone using Veeam products and for Veeam. Veeam builds great software, has stellar support and delivers the value I look for in an ISV.

So to Veeam, thank you for the trust in me, my skills and professional abilities to make me a Vanguard in 2017. I’m happy and proud to be one.

VeeamOn 2017 Call for Presentations

Veeam will be holding its annual conference VeeamOn 2017 in New Orleans, Louisiana on May 16th – 18th. You can actually already pre-register for the conference today. Just follow this link. This qualifies you for a 200$ discount.

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But don’t stop there. When you work with Veeam products you might have some interesting solutions and experiences to share. Maybe you got creative and designed a smart solution to you needs. That’s something that can inspire people to think about how they use the products. So please, don’t be shy. Consider submitting your proposal for a presentation at VeeamOn 2017. Help your peers to achieve their needed availability in an always-on world. Go to https://www.veeam.com/veeamon/call-for-presentations and share your experience, knowledge and insights.

I hope to see you there to learn form and be inspired by you, my peers and colleagues from all over the world!

Veeam Leads the way by leveraging ReFS v3 capabilities

Introduction

You might have noticed that I’m pretty impressed by what Microsoft is doing with ReFS v3 in Windows Server 2016. You can read some of my musing on it in ReFS vNext Block Cloning and ODX and take a look at a comparison between ReFS & ODX speeds when creating VHDX files in Lightning Fast Fixed VHDX File Creation Speed With ReFS on Windows Server 2016 .

Note that this is also leveraged for accelerated checkpoint merges, VHDX resizing etc.

Now it goes without saying that Hyper-V (they’re the tip of the spear at MSFT) and other Microsoft products would take advantage of the capabilities of ReFS. But now we know that Veeam Backup & Replication 9.5 has made use of ReFS to help with the resilience of their backups, the speed of their Synthetic Full backups and the space required.

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To a Hyper-V MVP and a Veeam vanguard it was obvious these two combined just had to lead to way for others to follow.

Veeam Leads the way by leveraging ReFS v3 capabilities

Veeam Backup & Replication 9.5 will leverage ReFS v3 …

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and by doing so they deliver the following benefits:

  • Shorted backup windows and a reduced backup storage load on the repository
  • Reduced backup target storage capacity which is reducing or eliminating the need for deduplication in many scenarios.
  • Better backup data protection by leveraging the ReFS native capabilities to protect against bit rot which was one of the prime goals for which Microsoft designed ReFS.

How is this done?

ReFS v3 has “fast cloning” technology which Veeam is leveraging. This results in up to 10 times  faster creation and transformation of synthetic full backup files!  ReFS fast cloning allows for creating new files without physically moving data blocks between files. This is what delivers even shorter backup windows and lower backup storage load on the repository or repositories.

They use what they call “Spaceless full backup technology” which allows multiple full backup files to reside on the same ReFS volume that share the same physical data blocks. As a result they need less storage capacity which can reduce or eliminate the need (and cost) of deduplication appliances whilst leveraging commodity storage.

Lest see how this is done. A “legacy” full backup is created an consumes 30% storage capacity. Then we make incremental backups.

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3 incremental backups add 3 * 10% of delta to the needed backup storage capacity which adds up to 60%.

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We create a synthetic full backup and the copies of the data require another 30% of space (90%). 

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No let’s compare this to v9.5 that leverages a Windows Server 2016 ReFS formatted backup target repository. Instead of copying data ReFS references already existing data block for a new file. This saves on IO, space and time!

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Is this safe? What if those data blocks that are reference multiple times are corrupted? Well Veeam does have protection against that in place already! But it goes the extra mile as ReFS has the capabilities to protect against that itself or it’s power would also become its biggest weakness.

Veeam’s data integrity streams integration leverages ReFS data integrity scanner and even proactive error correction when used in combination with Storage Spaces to protect backup files from bit rot and allows for more reliable forever-incremental archiving. This helps make the spaceless full backup technology trustworthy & safe alongside the health checking & error fixing capabilities already available in Veeam Backup & Replication.

Conclusion

I’m impressed by the forward looking and fast adoption of the capabilities of ReFS v3 by Veeam and I’m testing Backup & Replication v9.5 Beta today in the lab. They have more up their sleeve by the way as they have some interesting work with PowerShell Direct to make backups ever more resilient in ever more scenarios. More on that later.

Anyone who said Veeam would lose its edge in the world of Hyper-V backups when Microsoft introduced their own native change block tracking (resilient change tracking) has clearly never dealt with Veeam seriously and professionally. I have and I’m always happy to chat to them as they have serious technical skills combined with vision and business acumen that makes sure they’re leaders in the business of backup. It makes me proud to be a Veeam vanguard and a MVP with a specialization in Hyper-V.