Forum Discussion
Cachestorage/Recovery vault for site recovery Manager best practices
What are the suggested best practices for Cache storage . What is the default recommendation on no of VMs that should be part of same cache storage . Where should the recovery vault for site replic...
Hi
- Use GPv1 storage when you are using a custom storage account cache .Usage of GPv2 is not recommended because transaction costs for V2 are substantially higher than V1 storage accounts . Also premium storage are not supported.
- The storage account can be in the same or a different subscription but should be in the same region as the virtual machines being protected
- Ensure that Allow trusted Microsoft services'. is checked in Firewalls and Virtual Networks when the access is allowed from Selected Networks and not from All networks . Also, ensure that you allow access to at least one subnet of source Vnet.
- Use multiple storage account when using large amount of virtual machines because there are some limits with the number of disks that can be replicated . Those limits are specific to Azure to Azure and zone to zone DR scenarios.
The table below can help to calculate how many storage account you would need for a given number of virtual machines and disks .
Storage account type Churn = 4 MBps per disk Churn = 8 MBps per disk
| V1 storage account | 300 disks | 150 disks |
| V2 storage account | 750 disks | 375 disks |
You can find the support matrix here and almost all the informations listed above
@ibrahimambodj
Thanks for that info.
It is the use case /purpose for which you are using a "cache" that I am interested in firstly.
- Cache storage is needed to copy the disks info in the source datacenter for DR purpose refer this article https://docs.microsoft.com/en-us/azure/site-recovery/azure-to-azure-architecture that show the Cache storage account You need a cache storage account in the source network. During replication, VM changes are stored in the cache before being sent to target storage. Cache storage accounts must be Standard.
