Hello everyone,
I’d like to get your opinion on a migration method I’m considering for moving from my DS718+ to a 4-bay Synology NAS.
My current DS718+ contains 2 × 6 TB drives. In practice, I only really use one drive for my production environment; the second one is used as a copy/backup of the first, so I would still have a safety copy during the migration.
My final goal on the new NAS would be:
4 × 8 TB in RAID 5, giving me roughly 24 TB of usable capacity.
I was thinking of doing the following:
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Remove the 6 TB drive containing my current environment from the DS718+ and physically install it in the new NAS.
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Perform the DSM migration on the new NAS so that I recover my data, applications, Docker containers, settings, etc.
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Add 3 new 8 TB drives.
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Expand/convert the storage pool to RAID 5 with 6 + 8 + 8 + 8 TB. If I understand correctly, the usable capacity would then be limited by the 6 TB drive, so around 18 TB usable.
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Once the RAID is fully built and healthy, remove the remaining 6 TB drive and replace it with a 4th 8 TB drive.
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Rebuild the RAID so that I eventually end up with 4 × 8 TB in RAID 5, giving me roughly 24 TB usable.
During the whole process, my second 6 TB drive would remain untouched in the DS718+, so I would still have a backup copy of my current environment.
Does this approach seem technically feasible and supported by DSM?
More specifically, is it possible to start from the existing storage pool on the 6 TB drive, expand it to RAID 5 with the three 8 TB drives, and then replace the 6 TB drive with an 8 TB drive in order to reclaim the full available capacity?
Or would you recommend creating a brand-new RAID 5 directly with 4 × 8 TB drives and using Migration Assistant instead?
Thanks in advance for your feedback and experiences!
It may be a copy, but it is not a backup. Backups only exist outside from the NAS. When things go sideways everything on the NAS will be lost.
You misunderstand. The “environment” … DSM, or whatever that means to you, is replicated across all drives. It’s best to follow the supported migration procedure:
Migrating your Synology NAS
As it is unclear exactly how your drives are set up, we can only guess. Follow the linked procedure for the best result.
Thanks for the feedback. I’ve actually revised my migration plan a little, so let me clarify my current setup and what I’m doing now.
My DS718+ originally had 2 × 6 TB drives configured as two completely separate storage pools/volumes — no RAID.
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Volume 1 / Drive 1 (6 TB) is my main volume. It contains my applications, Docker environment and all my main data.
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Volume 2 / Drive 2 (6 TB) is only used as a backup destination for some of my most important folders using Hyper Backup.
I have now removed the second 6 TB backup drive and put it aside, untouched, so I still have a separate copy of my important data during the migration.
In its place, I installed a new 8 TB drive in the DS718+. I am currently converting the main 6 TB storage pool into RAID 1 using the existing 6 TB drive + the new 8 TB drive.
Of course, at this stage the RAID 1 capacity will remain limited to approximately 6 TB because of the smaller drive.
Once the RAID 1 has been fully built and is healthy, my idea is to use this newly created RAID 1 as the starting point for the physical migration to the new 4-bay Synology.
I would then progressively replace/add drives on the new NAS until I eventually reach my final configuration of 4 × 8 TB in RAID 5.
So my plan is no longer to migrate a single Basic 6 TB drive. I will first have a healthy 6 TB + 8 TB RAID 1 on the DS718+, while keeping my original second 6 TB backup drive safely aside as an additional fallback.
The RAID 1 conversion/rebuild is currently running and DSM estimates that it will take around 5–6 days to complete.
Once that is done, I would like to physically migrate the RAID 1 drives to the new NAS and continue the storage migration from there.
I would have chosen SHR instead, as it would allow you to gain capacity beginning with the next added drive.
Without a true external backup you are gambling that you will be able to access the data on the removed drive. Good luck.
I actually do have a separate backup.
The original second 6 TB drive, which contains my Hyper Backup of the important data, has been physically removed from the NAS and is currently sitting on my desk, untouched.
The DS718+ is now using the original 6 TB production drive together with a new 8 TB drive to build the RAID 1. (on the second drive slot)
So the backup drive is completely separate from the RAID operation currently in progress. If something goes wrong during the RAID 1 conversion, that backup drive is not involved or connected to the NAS.
That’s why I’m not quite sure what you mean by “gambling that I will be able to access the data on the removed drive.”