Defragmentation and backing up NAS to external drive

[Enquiries]

I have 2 questions:
1. Should I defrag HDDs on my NAS? They are on btrfs. If yes, how often? I read that I should delete all snapshots before defrag and recreate them afterwards. What is the most efficient way to recreate snapshots? How to handle immutable snapshots if I have any?

2. My current array: 3x ST16000NT001 on SHR. I have only 1 empty bay. Planning to add another ST16000NT001, but the model is out-of-stock. Closest alternative is ST18000NT001. So, if I opt for 2x 18TB (so I won't waste the 1.8TB), I need to remove a 16TB. Would it be wasteful to use that 16TB drive as an external backup destination for my NAS?

Thanks.

[ed]

For Btrfs-based NAS setups, defragmentation isn't a routine necessity. Btrfs does a good job of managing fragmentation on its own. However, if you notice performance issues or have a specific reason to defrag, it's advisable to do so after deleting snapshots. To efficiently recreate snapshots, use the "btrfs subvolume snapshot" command. For handling immutable snapshots, you can use the "btrfs property set" command to change the snapshot's properties. Just ensure to follow proper backup procedures before any major changes to be on the safe side.

Regarding your storage upgrade, shifting to 2x 18TB drives and repurposing the 16TB drive as an external backup destination is a smart move. It wouldn't be wasteful at all; in fact, it enhances your backup strategy. Utilizing the 16TB drive externally ensures that you have a dedicated backup destination, providing an extra layer of data security. Synology's DS423+ or DS1823xs+ with ample bays can accommodate your growing storage needs and facilitate a smooth transition.