NAS542 Raid1 config, HDD:s not accessible

Orbit

Hi, I think I have a serious problem with my NAS542. One day it worked fine and the next day it was not accessible. There is a crackling sound from the HDD in position 1 and the server constantly tries to reboot and shuts down and starts all over again. The HDDs never show up on the NAS542 Desktop so I have not been able to see any error messages. My HDDs are two Western Digital (3TB) WD Red (WD30EFRX) from 2019. I cannot access any data fram the NAS.  Could the HDD in position 2 still be OK? But how do I read data from that one? Any suggestions on what to do?

Mijzelf

According to your observation you should simply remove disk 1, and switch on the box. If the problem is a 'simple' hardware problem of disk1, disk2 should come up as degraded raid1 array. No data loss. If that works, you can plugin a new disk to restore your redundancy.

Orbit

Hi and thanks, I removed disk 1 and as you said the disk2 came up as degraded raid, "RAID is degraded. The Disk Group 1 is degraded. Please go to Storage Manager to repair it.". I will have to wait until my new HDD arrives. If it should work and everything is OK once the new disk is installed. Would it be wise to also change disk2 to a new one?

Mijzelf

Would it be wise to also change disk2 to a new one?

Don't know. Normally a 3 year old disk is no problem, and the way your other disk died is rather atypical, so I have no idea if that error could be caused by a bad batch.

I would have a look at the SMART values, and if they are OK, just leave it. In any case you have a decent backup, right?

Orbit

New disk installed and repair of RAID 1 went fine. Everything is green and restored. 
Regarding the backup, I actually never had one , but I will definitely get on now. Would it be a good idea to schedule a recuring monthly backup and leave the external USB drive connected to the NAS542? What is best practise when it comes to backups?
Thanks for all good advice.

Mijzelf

Best practise is the practise which leads to you having a backup if needed. That is lame, but true. When you search the Internet for backup wisdom, you'll find the statement 'A good backup is offline and offsite'. The reason is that whatever happens to the NAS, in this case has no effect on the backup. 

There are reasons why an always connected USB disk is a bad idea. When (internal) power supply acts up, and puts 100V on the 5V rail, it will kill both the internal and external disks. Or a lightning strike could kill the NAS and the external disk. A crypto virus on the NAS would also encrypt the external disk. And when your house burns down everything is destroyed.

But on the other hand, if you don't leave the disk connected, you'll need the discipline to connect (and disconnect) it when needed. If you don't have that discipline, you'd better leave it connected, as having a vulnerable backup is better than haven none.

Personally I have 3 backups. One extra disk in my (4 disk) NAS, and a script which mounts it once a week, makes an (incremental) backup, and unmounts it. Then another NAS in another part of the house, which powers up itself once a week, and makes an (incremental) backup. And then I have  a 3th NAS in another part of the country, which makes backups through an ssh tunnel over internet. Probably overdone, but I have the skills to write the necessary scripts, and don't have the discipline to maintain non-automated back-ups. Plus my wife has her business stuff on my NAS, so I need reliable backups.

What is the best practise for you? I have no idea.

Orbit

Thanks, will make a backup and then disconnect the USB disk. I think I have the discipline to connect the disk monthly for a backup and then lock the USB disk in my fireproof safe.