Source
r/synology•
atwright147

Best way to DS918+ Migrate shares from old RAID1 to SHR with some new HDDs?

I have a DS918+ with an existing 2x 3Tb WD Reds in RAID 1 (migrated from an old Synology 2 bay NAS).

I recently bought 2x 6Tb WD Reds and I would like to convert them all over to a single SHR1 volume.

My question is, what is the best way to accomplish this. My current thought is to create a volume on the 6Tb drives and move the shares over to that. Wipe the 3Tb RAID 1 volume, create an SHR volume there and move the shares back onto that volume. Then, wipe the 6Tb drives and add them to that volume.

This is all based on having read something about only being able to add disk to an SHR volume that are the same size or bigger than the first drives in the volume (hence starting with the 3Tb drives).

Does that sound reasonable or should I copy the files off to another HDD, do all of the volume creation and then copy back? What would be the fastest solution?

Posted Apr 19, 2019, 4:52 PM UTC

14
fryfrog•

I don't think I'd have the patience for that much shuffling.

I'd make the 2x 6T disks SHR1 and just leave the 2x 3T disks as their own volume. Split your storage of things between them. When you're ready to go bigger, just add a 3rd 6T+ disk to the new volume, move all the 3T data to that one and retire it. Put another 6T+ disk in when you need space again.

3
BakeCityWay•

That middle paragraph sounds like the best way. Internal transfers are going to be the fastest

2
jasper_DJ•

Given that the 3TBs are old, and 3TBs are known to have a higher failure rate, I’d just replace the 3TB drives one at a time and run 2x6TB in RAID1 until you can afford a 3rd 6TB, then add the 3rd and convert the RAID1 to SHR. You can sell the 3TB drives or repurpose them.

This approach gives you all new drives, of the same relative performance (the 3TBs would be slower than the 6TBs and reduce SHR pool performance), and you’d end up with 3TB extra storage than running two sets of RAID1.

2
atwright147OP•

Hey, thank you for being so generous with your time :)

I have taken onboard everything you have all said and after deliberating over the weekend, I have decided (based on what jasper_DJ said about 3Tb drives being slow and un-reliable) to buy two more WD Reds. Annoyingly though, I replaced one of those WD Red 3Tb HDDs in February as one was giving health warnings -- I guess I will just have to stick them in my Dell T5500 virtualisation homelab box.

And my new plan is to get DSM to move the shares to the recently created SHR volume, then add the other two drives to give me 18Tb of storage (as calculated by the Synology Raid Calculator). Does that sound alright?

1