Need help to change HDD after 1 disk failure (Raid 1)

[ohdan]

Hi, I am using AS3202T, a 2-bay NAS.

I was running a Raid 1 configuration with 2x 6TB Western Digital Red HDDs. Recently, the HDD in disk bay 2 has a status of media error from bad sectors.

I wanted to take the chance to progressively change the drives to 10TB ones. Ideally, I want to change out just the bad HDD to a 10 TB and have a Raid 1 with 1x 10TB disk and 1x 6TB disk. If that's not possible, I'll like to run 2x 10TB HDDs.

I tried a few things but can't find a way around this. Have tried:
1. Power down the NAS. Change out bad HDD to new 10TB HDD. Reboot NAS and it enters a fresh volume set up screen with a total reformat of both drives. I stopped here.
2. Hot swap the bad HDD to new 10 HDD. New HDD shows inactive and with no further action.
3. In the original configuration, I use the RAID function and went the route of "upgrade to larger HDDs". This requires me to change out disk 1 first, which is the "good" HDD. So I power the NAS down, change the good HDD to disk 2 and bad HDD to disk 1. After I turned the NAS on, it went into a 10 hour synchronisation but the NAS works as normal. After this, I did "upgrade to larger HDDs again". I switched out disk 1 to the new 10TB HDD but nothing happens. Status of HDD shows as "Inactive".

Hope someone here has a solution to this. Thanks.

[Nazar78]

To answer your first question, yes you can use 6tb and 10tb disks in raid 1 but you will only get 6tb of space raid 1. I have never tried this but I don't think ADM will allow you to use the remaining space as a single volume though you can try force it unofficially.

As for your second question, can you verify the new 10tb is not faulty? Try initialize only the 10tb then run badblocks scan or full smart scan (warning, do not place the old disks in bay while testing, mistakes can happen).

Edited: I can't recall but I think you can run the badblocks/smart scan even if the disk is not initialized.

[ohdan]

Thanks Nazar.

The new 10tb is new out of the box so unlikely to be faulty. If I initialize only the 10tb as a fresh volume, will the Asustor raid controller forget about the previously Volume of the 2x 6TB drives? My concern is that I won't be able to recover the old Raid 1 data after this.

[Nazar78]

Even new out of the box can be DOA. Just to rule out this issue. Have you tried my previous edited comments? Please try it first. You can also test this 10tb on a PC if you have.

Asustor is not using a hardware raid controller it's software based, known as mdadm. Also it's safe to put aside your raid 1 disks and reinitialize only the single 10tb. You can cold swap back after testing.

[ohdan]

I have verified that the new 10tb disk is not faulty. I have bought another 10tb disk and it doesn't rebuild as well. Shows as inactive. Both disks are not faulty.

The ADM simply does not rebuild the 10tb disk. Also, as I need to swap the disks, everytime I insert the bad HDD, it takes 10 hours to rebuild and then shows a media error. I'm concerned this continued 100% reading of the good HDD will cause it to degrade and I hope it doesn't degrade to the point of data loss before I can move the data to the new HDDs.

Any other suggestions?

[orion]

Try to steps:

• Power NAS off, and remove the cover of NAS. Although your NAS does provide hot-swappable slots, you'd better to hot-swap disk for this procedure.
• Power NAS on with old disks (2 6TB disks).
• After NAS started (it's all right if NAS is rebuilding), remove the failed disk (don't power NAS off). NAS rebuilding should stop. That's correct.
• Insert the new 10TB disk. NAS should start to rebuild. Wait for rebuilding to complete.
• Remove the left 6TB disk. Insert the other new 10TB disk. Wait for rebuilding to complete.
• Enlarge the volume size under ADM web -> Storage Manager.
• After completed, power NAS off. Put NAS cover back. Then, power it on.