Re-Initializing Drive in DS218+

[ronfel]

I know this is a very basic question but my Synology skill set is small. I would appreciate some help.

I have a DS218+ that has been running for more than a year with no issues. RAID 1 with Drive 2 mirroring Drive 1 (WD 4TB). Seems recently that Drive 1 became dislodged/disconnected when the area the NAS is located was being cleaned. One day I noticed that no drive was showing in slot 1. All was good with drive 2. I had someone push the drive back in place (I am out of the country) and now drive 1 is showing that it is not initialized and drive 2 is designated as Storage Pool 1. Not sure what to do to get things back to their original state.

 

[fredbert]

Hi. Since you have a degraded RAID 1 array I would have expect an option to restore the array with Drive 1.


Can you provide screen shots of Storage Pool 1 and Volume 1 (there may be small, faint grey v icons at the far right that should clicked to be showing ^, this exposes the details).

Here's mine. You can see I have storage pool 1 with a RAID type of SHR with 1-drive tolerance (a.k.a. SHR-1): in my 4 drive array this is like RAID 5. Below you will see my volume 1 is formatted using Btrfs file system.

 

[ronfel]

Hi. Since you have a degraded RAID 1 array I would have expect an option to restore the array with Drive 1.


Can you provide screen shots of Storage Pool 1 and Volume 1 (there may be small, faint grey v icons at the far right that should clicked to be showing ^, this exposes the details).

Here's mine. You can see I have storage pool 1 with a RAID type of SHR with 1-drive tolerance (a.k.a. SHR-1): in my 4 drive array this is like RAID 5. Below you will see my volume 1 is formatted using Btrfs file system.

View attachment 10542
View attachment 10541

 

[fredbert]

OK. Your storage pool 1 isn't RAID 1 but SHR without any protection. That's odd because if you had built the array as SHR with two drives it would have become SHR-1 (like RAID 1). But when Drive 1 was dislodged I would expect Storage Manager to tell you that storage pool 1 is degraded, not Normal and Healthy.

It looks like your Drive 1 has never been part of storage pool 1. The two options in Manage Available Drives that I would consider are:

1. Change RAID type: but there isn't normally a change when adding a second drive to an SHR array, unless moving to SHR-2. I don't think it is this option.
2. Add drive for storage expansion: Though this is only shown when "Synology Hybrid RAID (SHR) consisting of at least two drives" but you have only one drive. It does seem more likely than the other options.

When adding a second drive to a single drive SHR array it will not increase your storage but will make it SHR-1. The array will now have one drive tolerance.

However, before doing any changes to your storage pool and volumes you should first make a backup of the NAS in case something goes wrong.

Add Drives to Expand the Storage Pool Capacity
Choose a RAID Type
HDD/SSD

 

[Telos]

It looks like your Drive 1 has never been part of storage pool 1. The two options in Manage Available Drives that I would consider are:

Let's take a time out. It seems the OP has little sense of what system was used (RAID1 vs SHR). Given the fact that there was no degradation alert, it there are two possibilities.

1. The drive has never been placed in service... If this is the case, adding the drive options mentioned by @fredbert are surely viable.
2. The drive was formerly a separate SHR volume... If this is the case, it is possible it contains files which would be irreversibly lost if this drive was added to the existing pool.

OP needs to think this out carefully before proceeding.

 

[ronfel]

Thanks. I can say that the Drive 1 had been in service and that Drive 2 currently has all my files. I have a backup on Synology C2 so I feel I can take some risk. As to what has happened to get me to this state - no idea other than Drive 1 getting knocked out of the slot.

 

[fredbert]

2. The drive was formerly a separate SHR volume... If this is the case, it is possible it contains files which would be irreversibly lost if this drive was added to the existing pool.

Good point. But if Drive 1 has been a separate pool before then It's odd that it's not detected as a retrievable Basic or SHR (no protection) storage pool. Saying that, it's odd that actual storage pool 1 isn't degraded, if it was originally built with two drives.

 

[fredbert]

I have a backup on Synology C2

Which is good news.

 

[Telos]

Which is good news.

Well .... OP did say "C2"...