Home Synology: Moving Photos and Films to a New NAS

The short answer: There are three ways to move data from a Synology to a new NAS. You can move healthy, compatible drives, use Migration Assistant between supported models, or perform a clean installation and restore the data from a backup. For a business, the safest option is usually a new NAS with new drives, a verified backup and a procedure that leaves the old NAS unchanged until the result has been checked.

Which of the three methods should you choose?

Migrating Synology data to a new NAS involves more than simply moving the drives and switching it on. The right method depends on the exact pair of models, DSM versions, drive condition, volume type and whether you intend to keep using the old drives.

The fastest method is not necessarily the safest. Moving the drives avoids copying the data, but it also transfers ageing drives, the limitations of the original array and any existing file-system errors to the new device.

RAID and SHR are not enough before migration

SHR, RAID 1, RAID 5 and RAID 6 are not backups. They only protect against the failure of a certain number of drives. They cannot help if you make a mistake in the initialisation wizard, delete a folder, damage a volume, suffer a ransomware attack or encounter an error during migration.

You must therefore have a verified copy outside the drives being migrated before making any changes. A green icon beside the latest Hyper Backup task does not prove that the backup is valid. Open several documents, databases and large files directly from the backup, or perform a trial restoration to another folder. The article The 3-2-1 Backup Rule explains why a single copy is not enough.

You should also prepare:

• a DSM configuration export in a .dss file (Control Panel → Update & Restore),
• the password or key for the encrypted backup,
• keys for encrypted shared folders and volumes,
• a list of users, groups and shared folders,
• QuickConnect, DDNS, VPN and domain details,
• an overview of installed packages and licences.

Do not begin the migration if Storage Manager reports the array as Degraded or Crashed, or a drive as Warning, Critical or Failing. Copying reads entire drives, and that workload may cause a weakened HDD to fail completely. The guide How to Read Drive SMART Data explains how to interpret the individual values.

When can you move the original drives?

Moving the drives is suitable when you want to retain the existing array and the drives still have a reasonable service life ahead of them. The new NAS must support their interface, capacity and number. You cannot install a four-drive array in a two-bay model.

Having enough bays is not sufficient, however. Synology has its own rules for migration between product ranges, and not every pair of models will appear as Migratable in the wizard. Check both devices by their exact model names, including the suffix, because the DS224+, DS223j and RS822+ belong to different product ranges.

A typical reason for moving the drives is that the old NAS no longer starts even though its drives remain healthy. Well-known examples include models with the Intel Atom C2000 processor, such as the DS415+, DS1515+, DS1815+ and DS2415+. A defect in this processor can prevent them from starting after several years of operation.

Remove the drives only after shutting the NAS down correctly, and label their original positions. Synology recommends preserving their order. If the new NAS says that it will erase the drives when it starts, do not proceed. This is not a routine migration confirmation; it is a warning that the array will be lost.

You cannot change the layout when moving drives. You cannot convert RAID 1 to SHR, switch from ext4 to Btrfs or replace small drives with larger ones. DSM is reinstalled when moving between different models, packages often need reinstalling and network settings must be checked manually. Some packages, such as Surveillance Station or older multimedia applications, may require manual intervention.

When should you use Migration Assistant?

Migration Assistant is suitable when the old NAS works and the new one has its own drives. Both models must be on the list of supported devices. The destination must run DSM 7 in the same or a newer version than the source. Check the current Synology release notes for Migration Assistant to confirm the minimum DSM version required on the source.

You first create a new storage pool on the destination. This allows you to use new drives and choose a layout suited to the new device. Migration Assistant transfers entire volumes and checks whether the destination has sufficient space before it begins. Do not calculate the required capacity solely from the amount of data currently in use.

Data, system configuration, packages and their supported settings are transferred, but not everything is included. Network interfaces, the server name, default gateway, licences, Synology Account sign-in and some Virtual Machine Manager settings usually require manual attention.

One advantage is that the old NAS can continue operating during the main copy, with changes synchronised before the switchover. You must, however, set an exact point after which nothing may be written to the source. Otherwise, someone could save a new version of a document to the old NAS after the final synchronisation, and that version would never reach the new device.

Allow enough time for the transfer. A gigabit network has a theoretical maximum throughput of 125 MB/s. At a consistent 100 MB/s, transferring 8 TB takes approximately 22 hours. Large numbers of small files, data verification and slower drives will extend that time.

When is a clean installation the better choice?

Choose a clean installation if you want to change the storage structure, switch from ext4 to Btrfs for snapshots, build a different RAID layout or discard years of accumulated configuration. It is also the only sensible option if Migration Assistant does not support your pair of models.

On the new NAS, you create the pool, volumes, accounts and network configuration from scratch. You then restore the data from Hyper Backup, an external drive or another verified copy. Hyper Backup can back up the system configuration, including users, groups and shared-folder settings, as well as data with its permissions and the settings of supported packages. However, not every package backs up all its components.

To preserve permissions, restore the system configuration together with the data in the wizard. If you only copy the files over SMB, their contents will remain, but their original owners, ACLs and account associations may be lost.

A clean installation requires the most checking. However, it also allows you to separate company documents, computer backups, camera recordings and multimedia into new shared folders. The article A Home NAS for Photos and Films discusses how to choose the number and capacity of drives.

Drive compatibility in 2026

Synology’s drive policies have changed several times in recent years. DSM 7.3 permitted standard HDDs and 2.5-inch SATA SSDs from other manufacturers in Plus desktop models released in 2025, such as the DS925+ and DS1825+. Different rules apply to rack-mounted, enterprise and other product ranges. A drive that Synology identifies as incompatible is not the same as one that simply does not appear on its tested-drive list.

Always check compatibility for the specific destination NAS rather than relying on a general list of brands. WD Red Plus and Red Pro, Seagate IronWolf and IronWolf Pro, and Toshiba N300 drives are commonly used in storage arrays. For each exact model, check its capacity, recording technology and firmware.

Recording technology matters greatly in a RAID array. WD Red drives without the Plus designation in capacities of 2–6 TB, with model numbers ending in EFAX, use SMR recording. Such drives write significantly more slowly during an array rebuild, greatly extending the process. Choose CMR drives for RAID. WD Purple is designed for surveillance recordings and is not an automatic substitute for a NAS drive.

Drive prices change quickly. Compare the cost of two complete options rather than the price of a single HDD. The first is to retain healthy drives and keep a separate backup. The second is to buy new drives, use Migration Assistant and continue running the old NAS as a backup destination, for example with Hyper Backup Vault.

How to tell whether a migration is ready

The budget should cover the new NAS, drives, media for an independent backup and the work involved, including service checks. The cost cannot be determined solely by the number of terabytes. It depends on the number of volumes, installed packages, encryption, drive condition, network speed and the amount of downtime the operation can tolerate.

Before work begins, there should be a written plan containing:

1. the source and destination models, including their DSM versions,
2. the condition of every drive and the current RAID type,
3. the selected migration method and rollback procedure,
4. a list of services to test after the transfer,
5. a verified backup independent of the array being migrated.

Migration does not end when you can sign in to DSM. Check the shared folders, access for a standard user, SMB, backup tasks, Synology Drive, snapshots, notifications, the UPS, certificates and access from the computers that use the NAS.

When migration becomes data recovery

If the old NAS will not start, the array is degraded or a drive keeps disappearing, do not begin swapping drives at random. A failed rebuild writes across the entire array and can worsen the condition of the remaining drives. The article Recovering Data from a Synology NAS with SHR and RAID 5 explains how to proceed in this situation.

If the array contains data you cannot afford to lose and you do not want to risk experimenting with it, we can recover the data from your NAS drives. We will then migrate it to the new Synology only after creating a safe copy.