The website has been down for maintenance recently while i replace the HDD’s and expand my RAID volume in my NAS server. It seems 4TB just isn’t enough for my ever expanding film collection, you can thank High Definition and Blu-Ray discs for that. Anyway, i decided to purchase 4 x 3TB Western Digital RED NAS Edition (WD30EFRX) HDD’s to replace my ageing but still very reliable 1TB Samsung Spinpoint F1 HDD’s. This would give me a sizeable increase in storage capacity and hopefully mean i won’t have to upgrade again for some time.
My intention was to replace 1 HDD at a time and then expand the RAID volume as suggested in the Synology FAQ. Unfortunately this wasn’t possible as the original RAID volume was created by the binary “mdadm 0.9 version”. The new one is the mdadm 1.2 but a 0.9 mdadm volume can’t be converted directly to a 1.2 volume. This was completely unexpected and stopped me in my tracks.
The error message i got when selecting ‘Repair Volume’ is shown below:
“The volume is created with a previous version of DSM which does not support hard disks larger than 2TB. To use hard disks larger than 2TB, please create a new volume with the latest version of DSM”
I consulted Synology Technical Support (Who were fantastic coincidently, very knowledgeable, helpful and prompt to respond) and they suggested the following resolution:
- Upgrade DS to DSM4.1 (I already had the latest version)
- Create a new Volume2 with the 3TB disk (this one will be new volume type which supports 3TB disks fully) and create a folder backup on it. Using the function “Local Backup” to backup the data from Volume1 to Volume2. (Luckily there was sufficient space to do so with the new 3TB disk)
- Delete the Volume1 and recreate a new one Volume1 with three 3TB disks. This time the Volume1 will be new type, Synology Hybrid RAID or ‘SHR’. Then restore the data from Volume2 to Volume1 by the function local backup.
- After restoring the data from the Volume2 to Volume1, delete the Volume2 to release the 3TB disk.
- Join the 3TB disk to Volume1 and expand the Volume. There is a tutorial here on how to expand a volume.
I followed these steps to the letter and now i have a new volume 1 which consists of 4x 3TB Western Digital RED NAS Edition HDD’s. Importantly i haven’t lost any data and all my settings have been restored which saved me a lot of manual tinkering. While this process has been fully successful it hasn’t been without incident. Firstly i was expecting to be able to expand the original volume which wasn’t possible, and there was no indication on any forum or website that this wouldn’t be possible. Secondly the whole upgrade process has taken considerable time to complete, rebuilding a 3TB raid array is not a quick process, and copying data back and forth from different volumes and external disks (golden rule – always take a backup) also took a long time.