Options for using a Veeam Backup Repository on an Azure Virtual Machine
January 2015 update:
In December 2014, Microsoft announced the Public Preview Availability release of Azure Premium Storage. See this post for details on Azure Premium Storage features. What does that mean in terms of using Azure for a Veeam Backup Repository, or for Veeam Cloud Connect?
- Maximum disk capacity per VM remains a bottleneck at 32 TB.
- Only D14 VM size at this time can have 32x 1TB Page Blob disks. It comes with 16 cores, 112 GB RAM, 127 GB SAS system disk, 800 GB SSD non-persistent temporary drive ‘d’ that delivers 768 MB/s read or 384 MB/s write throughput. Base price for this VM is $1,765/month
- If using 32 Standard (spinning SAS) disks, set as a 16-column single simple storage space for maximum space and performance, we get a 32 TB data disk that delivers 960 MB/s throughput or 8k IOPS (256 KB block size).
- 32x 1TB GRS Standard (HDD) Page Blobs cost $2,621/month
- 32x 1TB LRS Standard (HDD) Page Blobs cost $1,638/month
- If using 32 Premium (SSD) disks, set as a 16-column single simple storage space for maximum space and performance, we get a 32 TB data disk that delivers 3,200 MB/s throughput or 80k IOPS (256KB block size). Premium SSD storage is available as LRS only. The cost for 32x 1TB disks is 2,379/month
- If using a D14 size VM with Cloud Connect, setting up the Veeam Backup and Replication 8, WAN Accelerator, and CC Gateway on the same VM:
- 16 CPU cores provide plenty adequate processing for the WAN Accelerator which is by far the one component here that uses most CPU cycles. It’s also plenty good for SQL 2012 Express used by Veeam 8 on the same VM.
- 112 GB RAM is an overkill here in my opinion. 32 GB should be plenty.
- 800 GB SSD non-persistent temporary storage is perfect for the WAN Accelerator global cache. WAN Accelerator global cache disk must be very fast. The only problem is that it’s non-persistent, but this can be overcome by automation/scripting to maintain a copy of the WAN Accelerator folder on the ‘e’ drive 32 TB data disk or even on an Azure SMB2 share.
- In my opinion, cost benefit analysis of Premium SSD Storage for the 32-TB data disk versus using Standard SAS Storage shows that Standard storage is still the way to go for Veeam Cloud Connect on Azure. It’s $740/month cheaper (31% less) and delivers 960 MB/s throughput or 8k IOPS at 256KB block size which is plenty good for Veeam.
Microsoft announced a new “Azure Premium Storage”. Main features:
- SSD-based storage (persistent disks)
- Up to 32 TB of storage per VM – This is what’s relevant here. I wonder why not extend that capability to ALL Azure VMs??
- 50,000 IOPS per VM at less than 1 ms latency for read operations
- Not in Azure Preview features as of 10/21/2014. No preview or release date yet.
High level Summary:
Options for using Veeam Backup Repository on an Azure Virtual Machine include:
- Use Standard A4 VM with 16TB disk and about 300 Mbps throughput (VM costs about $6.5k/year)
- Use a small Basic A2 VM with several Azure Files SMB shares. Each is 5 TB, with 1 TB max file size, and 300 Mbps throughput.
Not an option:
- Use CloudBerry Drive to make Azure Block Blob storage available as a drive letter. This was a promising option, but testing showed it fails with files 400 GB and larger. It also has a caching feature that makes it not adequate for this use case.
An Azure subscription can have up to
50 Storage Accounts (as of September 2014), (100 Storage accounts as of January 2015) at 500TB capacity each. Block Blob storage is very cheap. For example, the Azure price calculator shows that 100TB of LRS (Locally Redundant Storage) will cost a little over $28k/year. LRS maintains 3 copies of the data in a single Azure data center.
However, taking advantage of that vast cheap reliable block blob storage is a bit tricky.
Veeam accepts the following types of storage when adding a new Backup Repository:
I have examined the following scenarios of setting up Veeam Backup Repositories on an Azure VM:
1. Locally attached VHD files:
In this scenario, I attached the maximum number of 2 VHD disks to a Basic A1 Azure VM, and set them up as a Simple volume for maximum space and IOPS. This provides a 2TB volume and 600IOPS according to Virtual Machine and Cloud Service Sizes for Azure. Using 64 KB block size:
This short script shows block size (allocation unit) for drive e: used:
$DriveLetter = "e:" $BlockSize = (Get-WmiObject -Query "SELECT BlockSize FROM Win32_Volume WHERE DriveLetter='$DriveLetter'").BlockSize/1KB Write-Host "Allocation unit size on Drive $DriveLetter is $BlockSize KB" -ForegroundColor Green
This should come to 4.7 MB/s (37.5 Mbps) using the formula
IOPS = BytesPerSec / TransferSizeInBytes
But actual throughtput was about 2.5 MB/s (20 Mbps) as shown on the VM:
and in the Azure Management Portal:
Based on these results, I expect a Standard A4 Azure VM when configured with 16TB simple (striped) disk, with max 8k IOPS will actually deliver about 35 MB/s or 300 Mbps.
2. Using Azure Files:
Azure Files is a new Azure feature that provides SMB v2 shares to Azure VMs with 5TB maximum per share and 1TB maximum per file.
Testing showed that throughput upwards of 100 Mbps. Microsoft suggests that Azure Files throughput is up to 60 MB/s per share.
Although this option provides adequate bandwidth, its main problem is that it has maximum 1 TB file size which means maximum backup job is not to exceed 1 TB which is quite limiting in large environments.