The short answer: The safest approach is to set up the new NAS with new drives, create a full backup, test a restore from it, and transfer the data over the network using Migration Assistant, Hyper Backup, rsync, or QNAP HBS 3. Only move the original drives between models that Synology explicitly lists as compatible. Do not erase the old NAS until you have verified the data, permissions, applications, and restore process on the new device.
Migrating to a new NAS does not start with removing the drives
A new NAS is usually purchased because the existing system is running out of space, has a slow processor, is no longer supported, or cannot run newer applications. Copying the data itself is often the less risky part. The greatest risk arises when the old NAS is dismantled before a verified backup and rollback plan are in place.
Migration is not the same as replacing a single drive or upgrading a NAS with larger drives. In addition to files, you must transfer user accounts, permissions, encryption keys, network names, applications, and backup jobs. The files may therefore be intact on the new NAS while the company is still unable to access them.
A generic guide from an old forum is not enough. The correct procedure always depends on the exact models, the DSM or QTS version, the volume type, and the specific drives involved.
What you need to document before migration
Start by taking an inventory. „We have a four-bay Synology" is not enough information.
Record:
- the exact model of the source and destination NAS;
- the version of DSM, QTS, or QuTS hero;
- the model and health of every HDD, SSD, and any NVMe cache;
- the array type: RAID 1, RAID 5, RAID 6, RAID 10, SHR, or SHR-2;
- the file system, such as Btrfs, ext4, or ZFS on QuTS hero;
- the used and genuinely available capacity;
- shared folders, quotas, users, groups, and ACLs;
- encrypted folders or volumes and where their keys are stored;
- packages such as Synology Drive Server, Active Backup for Business, Hyper Backup, Surveillance Station, Container Manager, or Virtual Machine Manager;
- the IP address, server name, SMB paths, certificates, and domain integration;
- devices and applications that write to the NAS, such as scanners, cameras, accounting software, or computer backup tools.
Check the full model number of each drive, not just the brand. WD Red Plus, WD Red Pro, Seagate IronWolf, and Toshiba N300 are product lines designed for NAS use. WD Purple is intended primarily for video surveillance recordings. Also watch out for older WD Red drives without the Plus designation, such as the WD20EFAX, WD40EFAX, and WD60EFAX. They use SMR recording and may therefore behave unpredictably while an array is being rebuilt or expanded. The article SMR Drives in a NAS: Why They Drop Out of the Array explains how to identify them.
The compatibility list for the specific NAS is what matters, not merely whether a drive uses a SATA interface. For 2025 Plus-series models such as the DS925+, Synology changed its rules for third-party drives during the year. Always consult the current compatibility list for the relevant DSM version instead of relying on experience with an earlier model.
Moving drives, Migration Assistant, or a network transfer?
| Method | When it makes sense | Main limitation |
|---|---|---|
| Moving the original drives | A pair of Synology models listed as compatible by the manufacturer, with a healthy array | You lose the easy option of returning to the old NAS while it is still operational |
| Migration Assistant | Supported Synology models, with new drives in the new NAS | It does not transfer every service, licence, and network setting unchanged |
| Hyper Backup | Synology systems with complex configurations or incompatible models | Requires storage space for the backup and subsequent restore |
| rsync or HBS 3 | Moving between brands, such as from Synology to QNAP | Primarily transfers data; accounts, ACLs, and applications must be configured separately |
Move drives physically only if Synology’s current migration table explicitly supports your exact pair of models. Having the same number of drive bays is not enough. The destination NAS must support both the volume type and the specific drive models. Before moving the drives, remove any read-write SSD cache using the proper DSM procedure, as it may contain data that has not yet been written to the array. Also record the order of the drives in the bays before shutting down the NAS.
If the new NAS does not display „Migratable„ or „Configuration lost" after the drives are inserted and instead warns that it will erase the data, do not complete the installation. In this situation, Synology recommends cancelling the migration and choosing another method (HDD migration requirements).
Migration Assistant preserves more of the system context, but it still does not create an exact replica of the device. It only works with supported models, and the destination must run the same or a newer DSM version than the source. Some network parameters, licences, Synology Account details, and parts of the configuration for services such as Synology Drive, Active Backup for Business, Hyper Backup, Snapshot Replication, VPN Server, and Virtual Machine Manager must be handled manually (Migration Assistant requirements).
When moving between brands, the disk array itself cannot be transferred. The new NAS must be initialised with its own drives, and the data copied using Hyper Backup, rsync, SMB, or HBS 3 on QNAP. A Synology DSM configuration cannot be converted for use on QNAP. Similarly, an array cannot be converted from QTS to QuTS hero. QuTS hero uses ZFS and requires the drives to be initialised again. The article Synology vs. QNAP for Business summarises the differences between the two platforms.
Here we treat migration as a business project involving an inventory, permissions and ACLs, applications, planned downtime, and formal written acceptance. If you only need to choose between the three options available for Synology—moving the original drives, using Migration Assistant, or performing a clean installation and restoring from a backup—our service website discusses them in Migrating Synology to a New NAS: Three Options.
A full backup must exist before the outage begins
RAID protects against the failure of a certain number of drives, not against mistakes made during migration. Before making any changes, create a separate full backup outside the array being migrated.
A green status on the latest backup job is not enough. Restore several different types of files, one complete folder including its structure, and at least part of the data from a critical application. Verify that the files open correctly and that you know the password or key for the encrypted backup. The article Backup Restore Testing: How to Perform and Document It explains the procedure.
Do not erase the old NAS immediately after the first successful login to the new one. During a network migration, leave it unchanged as a rollback point until the new NAS has been formally accepted. This is the main safety advantage of using new drives instead of moving the original array.
Four pitfalls that only appear after the switchover
A different system version. A newer system on the destination NAS may not support old packages or their databases. Do not blindly update the old NAS before migration. First verify the health of the drives, the backup, and the supported upgrade path between versions. Updating a degraded array introduces unnecessary additional risk.
Encrypted folders. The administrator password is usually not the key to the data. For every encrypted shared folder or volume, store the recovery key and the key-store password somewhere outside the NAS. With Hyper Backup, the outcome may depend on whether the encrypted folder was mounted when the backup was created. Restoring into an encrypted folder requires that the folder be correctly created and unlocked on the destination.
Permissions and ACLs. After a basic rsync transfer, the files may exist but belong to a different UID or group. Windows-style ACL permissions used by DSM are not transferred this way. Testing with an administrator account is not enough. Sign in as a regular employee, a manager, and an account used by applications. Test reading, writing, and renaming, and confirm that users cannot access locations they are not authorised to use.
Applications. A copy of a shared folder does not mean that Synology Drive, a database, a virtual machine, or a surveillance archive will work. Some packages require an export or a consistent backup, a fresh installation, and then reconnection to the data.
A safe step-by-step procedure
- Take an inventory and check SMART data and the health of the storage pool, volume, and cache.
- Verify the compatibility of the exact NAS and drive models, the DSM or QTS version, and the selected migration method.
- Create a full backup outside the array being migrated and test a restore from it.
- Prepare the new NAS, update it using a supported procedure, and create the destination storage pool.
- Transfer the first large batch of data while users are still working on the old NAS.
- Schedule a short period in which no writes are allowed, then stop applications, databases, and backup jobs.
- Perform the final synchronisation of all changes.
- Switch the SMB paths, server name, DNS, or IP address according to the prepared plan.
- Test the data, permissions, applications, a new backup run, and a restore.
- Shut down the old NAS, but do not erase it until the migration has been formally accepted in writing.
When physically moving drives, label the bays and shut down both devices completely. Do not move drives while either system is running. Do not confirm initialisation simply because the wizard offers a Continue button.
If you do not feel confident performing the move yourself, we can plan and carry out the migration for you, including restore testing and handover documentation. If something has already gone wrong and the storage pool does not start after the move or reports a volume error, do not initialise or attempt to repair anything else. A basic initial assessment of NAS and RAID arrays may be free of charge; we provide a quote in advance for analysing multiple drives or reconstructing an array. You can find the procedure on our Synology NAS data recovery page.
How to estimate downtime and cost
The volume of data in terabytes is not enough to estimate the duration. Millions of small files transfer much more slowly than a few large backup archives because every individual file adds metadata-processing overhead.
The theoretical maximum throughput of a 1GbE network is 125 MB/s. Even at this maximum, transferring 10 TB would take approximately 22 hours. Actual speeds are usually lower because of the drives, protocol overhead, metadata, and normal network activity. Estimate the duration by performing a trial transfer with a representative data sample over the same route. The first copy can run while the system remains in use. The outage then only needs to cover the final changes and the switchover.
The cost depends on the number of accounts and shared folders, applications, encryption, new drives, temporary storage, and the required downtime window. The quotation should list the hardware, migration, restore test, application verification, and documentation separately.
How to tell whether the migration is truly complete
Before accepting the new system, require at least:
- a comparison of the file count and data volume in each shared folder;
- checksums for selected critical files;
- access tests using standard user accounts;
- application start-up tests using their actual data;
- checks of certificates, notifications, the UPS, and time synchronisation;
- a successful new backup run and test restore;
- documentation listing the models, drives, array type, addresses, and key storage location;
- an agreed date and conditions for erasing the old NAS.
The migration is only complete when the company can work normally on the new NAS and also knows how to restore its data.
Frequently asked questions
Can I move the drives from my old Synology to the new one?
Only if Synology’s current migration table supports your exact pair of models and the destination NAS supports all the drives, the volume type, and the DSM version in use. Having the same number of drive bays does not guarantee compatibility.
Does Migration Assistant transfer absolutely everything?
No. It transfers the data and a large part of the configuration. Some licences, network settings, service-linked accounts, and packages still need to be checked manually or reconnected.
Can I move from Synology to QNAP simply by transferring the drives?
No. Create a new storage pool on the QNAP and transfer the data over the network, for example using rsync or HBS 3. Accounts, ACLs, and applications must be configured again.
What if I do not have the key for an encrypted folder?
Stop the migration and first check whether the folder can be unlocked on the original NAS. Neither the administrator password nor moving the drives to another device can replace a missing recovery key.
When can I erase the old NAS?
Only after comparing the data, testing permissions and applications, successfully backing up the new NAS, and completing a test restore. Until then, leave the old NAS powered off and unchanged so that you can return to it if necessary.
Where to find us
ITHOPE is a company based in Brno, Czechia: we do data recovery from disks, RAID and NAS, PC and laptop service and IT for business, all in our own lab at Viniční 3587/216, 615 00 Brno.
Phone +420 775 556 063 (24/7 line). You can bring the device in person, or send it by courier (Zásilkovna, PPL).