DSM 6.2 Expanding storage space and changing RAID type

[Johnb42]

Hello. I'm trying to do two things - replace half of my old, small drives with new, larger drives, and change my RAID type from RAID 6 to SHR.

My NAS is an 1817+ running DSM 6.2.4. It has eight bays, all full of 4TB drives, in one storage pool, in a RAID 6 array.

I have four new 8TB drives. I want to replace four of my old 4TB drives with the new ones. Once the new drives are in, I want to change RAID 6 to SHR so I can maximize the available space afforded by the new drives. I would like to do all this without losing any data if possible, but I can back up data and start from scratch if necessary.

I have been consulting support docs, but I'm still not sure of the best/fastest/most secure way to go about doing this. For instance: everything I have read says to swap disks one at a time. But if I put in the new disks that way, won't they all get added to the existing storage pool? And if that happens, will I even have the option to create a storage pool running SHR?

Thanks so much for any help.

 

[fredbert]

Welcome to the forum.

Unfortunately you can't migrate a RAID 6 to SHR. In fact there's no support for migrating RAID 6 to anything else. See the help page for the table...

Change the RAID Type of a Storage Pool | DSM - Synology Knowledge Center

Synology Knowledge Center offers comprehensive support, providing answers to frequently asked questions, troubleshooting steps, software tutorials, and all the technical documentation you may need.

kb.synology.com

The guidance is to step through replacing one drive at a time until all have been replaced with larger drives, then you'll have expanded storage but only at the end of the very long process.

Replace Drives to Expand Storage Capacity | DSM - Synology Knowledge Center

Synology Knowledge Center offers comprehensive support, providing answers to frequently asked questions, troubleshooting steps, software tutorials, and all the technical documentation you may need.

kb.synology.com

What backup do you have for the NAS?

 

[Johnb42]

Welcome to the forum.

Unfortunately you can't migrate a RAID 6 to SHR. In fact there's no support for migrating RAID 6 to anything else. See the help page for the table...

Change the RAID Type of a Storage Pool | DSM - Synology Knowledge Center

Synology Knowledge Center offers comprehensive support, providing answers to frequently asked questions, troubleshooting steps, software tutorials, and all the technical documentation you may need.

kb.synology.com

The guidance is to step through replacing one drive at a time until all have been replaced with larger drives, then you'll have expanded storage but only at the end of the very long process.

Replace Drives to Expand Storage Capacity | DSM - Synology Knowledge Center

Synology Knowledge Center offers comprehensive support, providing answers to frequently asked questions, troubleshooting steps, software tutorials, and all the technical documentation you may need.

kb.synology.com

What backup do you have for the NAS?

Hi Fredbert! I see what you're saying, but at the moment I only have 4 new 8TB disks. For the remaining 4 bays, I'm going to have to keep using the old 4TB disks, which means I'll be stuck at 24 usable TB under RAID 6. I have enough backup space for all my data (external hard drive). So can I 'start fresh' - i.e. begin a new storage pool with the new 8TB disks in an SHR array, then add in four old 4TB disks in the new SHR array? How do I do that while preserving the DSM?

 

[fredbert]

You should have a full backup of the NAS because whatever is tried you should have a fallback in case of losing the array.

Now if you want to create a SHR array based on 4 x4 TB and 4x 8 TB then there's no easy way or quick way to do this. This would require a full Hyper Backup of the NAS and then restore to the SHR array. While the DSM partition is replicated on each drive, independently of the storage array, I've never deleted all storage pools on a running NAS and, therefore, never created a new pool using some of the smaller drives and adding new larger ones.

If that works then you'll have saved a little time in preserving DSM configuration, but this is also [90%] saved in the HB task. What this won't preserve is any packages as they are installed into storage space and there's no official way to move packages between volumes.

@Rusty any advice on the best way to achieve this RAID 6 to SHR migration, that avoids a HB backup / blow any current setup / restore from HB?