Overview

At times, Kerio Connect may take a lot of time to complete a full backup. In some cases, it is taking too much disk space because the number of backups is enormous.

There are multiple factors that can affect the backup process; usually, the process is impacted by the lack of server or network resources. This article provides recommendations on how to increase backup speed and overall performance.

Solution

Please follow the recommendation below to optimize your backup speed:

Use SSD if possible; hard disk drive performance is the main factor that affects the backup process.
Enhance your server resources (i.e., upgrade the CPU and RAM).
Reduce the size of backup files (Kerio Connect Administration > Configuration > Archiving and Backup > Backup tab > Advanced). You can enter decimal values such as 0.5 (500MB).
Schedule a small number of Complete Backups (e.g., once a week).
Make sure that your antivirus is not scanning the Mail Store folder.
Conduct maintenance on the mailboxes to reduce the store size. Use the item-cleanout feature, or ask your users to delete old emails or save large emails as PST files.
Because the backup is single-thread, the process is expected to consume a lot of time to back up the big storages, i.e. 10,000+ folders with almost 2 million files amounting to 950 Gigabytes or more. In such cases, a backup can hogg the system resources causing the server to become slow.
Users having more than 100+ folders and Deleted Items/Deleted Mailbox folders still being backed up. It's adding up to the duration of the backup process. Consider deleting unnecessary folders.
On Linux and macOS, you can use an alternative backup tool:
rsync

Note: Kerio Connect locks the mailbox when performing a backup and unlocks it when the process is complete; hence, when using other backup methods, please stop the Kerio Connect service to avoid corruption.