Is there a guide available to replacing two 1TB drives in a raid in a DS220j to 2 x 4TB to increase capacity?
I have in mind 2 x Seagate Ironwolf Pro Seagate IronWolf Pro, 4 To, internal hard drive, NAS, 3.5 inch, SATA, 6 Gbit/s, 7,200 rpm, 256 MB cache, for RAID storage, 3-year backup service, FFP (ST4000VN-06).
My understanding is that the existing two drives can be replaced one by one but I have been unable to find a definitive step by step set of instructions for doing so.
My current version of DSM is 7.1 and Iām currently very happy with the current hardware which is working well without the need to replace it with something like the DS423 which I think will be overkill.
The use case is a simple home NAS for sharing files between workstations (all Ubuntu Linux), providing a homes directory for each user (mini PCs without additional storage capability) and video station for viewing films saved to the NAS on a smart TV.
Any guidance will be welcome.
Probably easier just to copy everything to a portable usb drive, swap out the old drives in your Synology with your new IronWolfās and copy everything back. Or even use Hyperbackup to backup and then restore it afterwards.
I donāt disagree with that.
Iām considering this device from Amazon.
The DS220j has 2 x USB 3.0 ports on the back.
Is it safe to assume that 4 TB will work in the NAS seamlessly?
I intend to use HyperBackup to complete this task as opposed to plugging a USB drive in to my Linux (Ubuntu) PC and using something like rsync to copy the files across natively.
Whilst 4 TB might seem overkill for a 1TB raid, it will allow versioning and will save me making the same mistake over in terms of under specifying size and capability should I later progress to a larger capacity NAS.
Attaching the USB directly to the NAS seems the only option as HB canāt see the device when attached to the PC and my existing 1TB backup drive in a USB enclosure is now perhaps getting a bit old.
Iāve got 5TB drives hanging off my 218 and even my old 213 and they both work fine.
Actually, doesnāt the HyperBackup app for PC let you view the contents of the .hbk file when the drive is attached to your computer?
Havenāt come across such an app - is it for Windoze or is here a Linux client and where can I find it?
What partition type are the drives formatted to? Ext4/NTFS/etc
This will help:
My 5TB drives are formatted ExFat.
@Martin_Walker
Mine formatted to Ext4 under HB (I donāt use other than Linux) and with the drive connected by USB to the NAS, after 16 hours with no other activity on the NAS, it had only backed up 70% of 618 GB so I cancelled it.
Is HB really that slow???
When I backed up using rsync under Linux - which copies the files natively - to the same device connected via my Linux PC, it completed in ā5 hours with the advantage that subsequent runs would take much less time since it would first compare what is on the target to what is on the source, remove any files on the target no longer on the source and only copy across new of changed files which would reduce the subsequent run times significantly.
As I understand it HB will kick off a completely new backup each time it runs (deleting the previous run in the process unless you ālock itā) so there appears to be no advantage over rsync - unless you can suggest otherwise, of course.
I think Iāll still go for the portable NVMe SSD but will test it out with both HB and rsync options to check on performance.
I donāt consider anything a Synology unit does quick, especially file operations, unfortunately. My understanding of how HyperBackup runs is that itās incremental depending on how many versions you want to keep. Iāve been moving large photo files between two NAS units over wifi and, dear god, itās an exercise in patience. 
At least itās not just meā¦ Iām just testing a new backup on a like for like basis with what I ran using rsync (ie no apps etc) to see how that compares and Iāll check up the incremental thing although that seems not to be what I read but does make sense. It might be better to separate out the different shares perhaps - such as data and video and perform them as different tasks.
If I had to use these things for any kind of video work I think Iād go mad. I wish I knew more about rsync enough to use it. I can see the benefits.
What OS are you using? In Linux, there is a GUI for rsync called luckyBackup which makes the whole process of setting up rsync intuitive.
The user guide is here for information.
You may also finf this reference useful - Iām going to study it closely.