Now I have 4x500gb in raid5 mode, want to upgrade to 4x2TB
Should I replace one of the disk, let it resync it and the replace the next one and so on?
That will work. Doing a backup first is recommended (as disks sometimes will fail during the resync).
The NV+ v1 won't expand storage until the last disk is upgraded (and that final resync will take a lot longer than the others). Not sure, but it might prompt you to reboot before expansion.
The other option is to insert all four 2 TB drives in the NAS and then power up. It will do a fresh factory install. You'd need to set up the NAS from scratch, and restore the data from backup. The volume build will be faster using this option, but of course you need to spend time restoring the data.
FWIW, I recommend getting either WD Red Plus drives (WD20EFZX) or Seagate Ironwolf drives (ST2000VN004). Avoid the WD Red (WD20EFAX) - it is an SMR drive, which is a technology that often has issues in ReadyNAS.
I'm getting a little bit scared by you're recommendation.. I have just the WD20EFAX) modell of drives 😮
To be fair, I haven't seen any posts either way from NV+ users. Several folks have had serious performance problems in newer ReadyNAS (OS-6 models that use the BTRFS file system - similar in many ways to ZFS).
We want to be very clear: we agree with Seagate's Greg Belloni, who stated on the company's behalf that they "do not recommend SMR for NAS applications." At absolute best, SMR disks underperform significantly in comparison to CMR disks; at their worst, they can fall flat on their face so badly that they may be mistakenly detected as failed hardware.
With that said, we can see why Western Digital believed, after what we assume was a considerable amount of laboratory testing, that their disks would be "OK" for typical NAS usage. Although obviously slower than their Ironwolf competitors, they performed adequately both for conventional RAID rebuilds and for typical day-to-day NAS file-sharing workloads.
I don't recommend them, but they might be "OK" in your NAS. Still, if you just purchased them, you could exchange them for the Red Plus or Ironwolf.
