Replication free space required on storage

[Rohail2004]

Guys,

I have a 30GB source LUN which has 7GB free. How much free space required on a source LUN in order to replicate at the Target LUN Successfully?

[Gostev]

Hi, you need just enough to accomodate source VM snapshot growth while the replication job runs (which can be a few hours for initial run). Required disk space depends on workload of specific VM (how much disk changes it does). For example, if one of your VMs manages to change/write more than 7GB of data on its virtual disks, you will have a problem (source VM will stop due LUN having no free space to accomodate further writes).

Average VMs change 2-5% of virtual disk blocks daily, but those running Exchange or SQL can do 30-40% because of transaction logs.