How do you propose to do this...four WD30EFRX 3TB drives in RAID5, I’m thinking of adding a Seagate ST4000VN008 4TB drive and changing to SHR
Only certain RAID types can be changed to other RAID types. For example, RAID 1 can be changed to RAID 5, but RAID 5 cannot be changed to RAID 1. Please refer to the table below for details.
|Current RAID Type||Possible Conversion Target Type||Additional Number of Drives Required|
|RAID 1||RAID 5||1|
|RAID 5||RAID 6||1|
|SHR-1||SHR-2||1 or 2 (depending on the drive configuration of SHR)|
Sounds good, ive checked on the Synology RAID calculator, and using SHR, 3 x3TB plus two 4TB gives 13TB useable with 4TB for protection, but using one HDD in bod just for TM seems a interesting idea, one of my external backup USB drives has now disappeared from file station and Finder on my Mac ! but it shows up in control panel, external devices ??If you rebuild with 3x 3TB and 2x 4TB then you'll have a usable 14TB SHR-1 RAID. Whereas 4x 3TB and 1x 4TB results in 12TB.
But you can't start with with, e.g. 2 disks, with big TB and then expand with smaller TB disks: this just isn't supported.
You do have another option if you don't mind that the extra disk won't have any RAID protection: add the 4TB disk to the NAS and create a new Storage Pool of one disk using either SHR-1, Basic, or JBOD. If this disk fails then the data is gone, unless you back it up.
Depends what you want to store on it. I'm in the process of, finally, decommissioning a very old Iomega/Lenovo NAS used just for Time Machine and I've a spare 3TB WD that can go in the new DSM NAS. It's now new a JBOD single disk RAID (in case I want to expand it later ... I won't) and will be Time Machine until I decide what to do long term. But for me TM is not important in my backup process so this one disk RAID is ok to fail.
Ok, sorry, I’m new to Synology and this forum, I’ll definitely post new of my next question@David James Just FYI... but it's best to open a new thread when changing the topic. And provide a useful thread title (not "Changing Stuff") so it attracts folks who can help, and so others with similar issues can search for solutions to their needs.
Here we've gone from "Migrating from RAID 5 to SHR", to "Time Machine won't connect". Quite different from "Changing Stuff". Cheers!
I started a new TM backup to my DS a while ago, not failed yet, on over 200gb with 3 hours to go best yet, I remember it keeps saying something about having to start a new backupNormally macOS will display an alert to say something such as, paraphrasing: the TM destination is unavailable; the TM archive needs some maintenance [which is code for 'delete the current backup archive and start again'].