It is expected to have syncs during backups if they are set on local drives under VM - as this process generating a lot of IOPS for single time on day, and Zerto handling this by Bitmap syncs after buffer fills.

It is always recommended to perform backups to a dedicated NAS or storage subsystem in different network, so if something happens with VM - backups will be not affected. But if it's not possible to create architecture like that, and  you wanted to have low RPO values at any time.

However you can apply Temp data storage, on which all I/Os during your scheduled backup will be ignored and this volume will be not replicating to other side - this can be useful to avoid unnecessary syncs and alerts.

Using this setting will ignore all I/O on marked disk, and all changes to it, as Temp data disk transferred only once to DR site, and all further changes on this disk will be ignored.


To set this, you will need to do the following:

1. Edit your protected VM settings in hypervisor on which you have set backup process and add(create) a new volume;

2. Under protected VM - create the filesystem on the new hard disk and configure your backup processes to this new disk;

3. After partial initial sync ends(expected when attach new VMDK to VM), go to VPG settings >> Storage and mark new VMDK as Temp Data:

After this, all I/Os to this drive will be ignored, so during backup IO flow to protected disks will be normal.