Recently, I used the Migration Assistant to migrate data and system settings from the Synology DS1817+ to the DS1821+ NAS. Other than refreshing the NAS, a brand new set of 10TB hard drives replaced the existing 6TB. The migration was seamless and services remained available during the process.
Various Migration Options
Synology has several migration methods on the table, they are:
- Hard drives migration
- Migration via Migration Assistant
- Migration via Hyper Backup
I decided to go for Migration Assistant as I am refreshing the hard drives along with the NAS.
Usually I will just migrate the existing hard drives (Seagate IronWolf 6TB) to the new NAS but not this time round because they are out of warranty and I am in need of additional storage space.
Why not hard drive migration and replace drives with higher capacity?
Of course, I can migrate the existing hard drives over to the DS1821, replace the hard drives one-by-one and let it rebuild the RAID with each hard drive replacement. However, this process would be time consuming and incur unnecessary read-writes on the hard drives.
Then why not Hyper Backup?
One key requirement of using Hyper Backup is that you need twice the amount of storage capacity as the amount of data on the source Synology NAS. That is, if I have 30TB of data on my DS1817+, I will need 60TB of storage capacity on the DS1821+.
Even if I meet the storage capacity requirement, I would need a 30TB portable drive to move the backup data over without network for speed advantage. But if I will still be relying on network transfers, I might as well go for the Migration Assistant route.
My experience with the Migration Assistant
The migration to the new DS1821+ NAS took around three days for 27TB of data over my Gigabit network. During migration, the services are still available on the source NAS (DS1817+) and migration assistant adjusts its transfer speed to minimise impact to the services. Hence, services like Synology Drive, DS Cloud and Docker continue to serve the clients.
Before the actual cutover to the new NAS, the Migration Assistant does a final check and re-syncs any data inconsistencies. Considering that we cant avoid adding or removing data during the migration period, this is a great feature.
All in all, I am happy with the Synology Migration Assistant.
Make full use of the link aggregation feature on both the source and destination NAS. Even if your network switch do not support link aggregation, you can use adaptive load balancing (under Control Panel > Network > Network Interface) to improve the network throughput. Do match the speeds on both the source and destination Synology NAS as there is no point having 4000 Mbps on one end and 1000 Mbps on the other.
You can pause and resume the migration when needed. If you need your source Synology NAS and network to continue providing services at peak performance, you can manually pause and resume the migration during off-peak hours.
Some items are not migrated seamlessly
I observed the following packages/ settings are not enabled after the migration:
- The Docker images and containers settings were transferred but containers were not started
- Firewall profiles were transferred but not enabled
The following items that are not migrated:
- Community packages and settings
- Server name
- Self-defined static routes
- Desktop widgets
Guide on using the Migration Assistant