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Table Of Contents
Configuring Replications by Using Replication Seeds
When copying replication seed files to the target datastore, you can use the vSphere Web Client to create
a new root folder on a Virtual SAN datastore, or place the files in an existing folder. When you configure
replications that use replication seeds, you must select the folder by using its UUID name. Selecting the
user-friendly folder names is not supported.
Reconfiguring Replications
If you want to change the destination folder for a disk or the virtual machine config files, you must use the
following options:
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Select the UUID name of an existing folder.
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Allow vSphere Replication to create a new folder and obtain its UUID name.
Limits of Using vSphere Replication with Virtual SAN Storage
For reasons of load and I/O latency, Virtual SAN storage is subject to limits in terms of the numbers of
hosts that you can include in a Virtual SAN cluster and the number of virtual machines that you can run
on each host. See the Limits section in the VMware Virtual SAN Design and Sizing Guide at
http://www.vmware.com/products/virtual-san/resources.html.
Using vSphere Replication adds to the load on the storage. Every virtual machine generates regular read
and write operations. Configuring vSphere Replication on those virtual machines adds another read
operation to the regular read and write operations, which increases the I/O latency on the storage. The
precise number of virtual machines that you can replicate to Virtual SAN storage by using
vSphere Replication depends on your infrastructure. If you notice slower response times when you
configure vSphere Replication for virtual machines in Virtual SAN storage, monitor the I/O latency of the
Virtual SAN infrastructure. Potentially reduce the number of virtual machines that you replicate in the
Virtual SAN datastore.
Retaining Point-in-Time Snapshots when Using Virtual SAN
Storage
Virtual SAN storage stores virtual machine disk files as a set of objects and components. Each disk object
in Virtual SAN storage has mirror and witness objects. In the default Virtual SAN storage policy, a disk
object has 2 mirrors and one witness. The number of mirror components is determined by the size of the
virtual machine disk and the number of failures to tolerate that you set in your Virtual SAN storage policy.
A mirror object is divided into components of a maximum size of 256 GB each.
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If a virtual machine has one 256 GB disk and you use the default Virtual SAN storage policy, the disk
object will have 2 mirror components of 256 GB each and 1 witness, to make a total of 3 components.
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If a virtual machine has one 512 GB disk and you use the default Virtual SAN storage policy, the disk
object will have 4 mirror components of 256 GB each and 1 witness, to make a total of 5 components.
VMware vSphere Replication Administration
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