How long to add 16TB hard drive to a brand new storage pool?

[ColBat]

I have a new DS1621+ to recover from a #1 bay failure of my DS920+. As part of my change to the DS1621+ I opted to switch from RAID 10 to SHR. I have reformatted the first four drives (to exFAT using Windows Disk Manager) I'll initially install so they had nothing left from the previous Synology install. The drives are two 8TB drives and two 16TB drives. I want to eventually have two 8TB and four 16TB drives (all drives I have used in previous Synology NAS') all in one storage pool, 80TB total. I set up the DS621+ first with one 8TB drive using SHR and establishing Storage Pool 1. I then added the second reformatted 8TB drive to Storage Pool 1. All has gone well and Storage Pool 1 shows Drive 1 (8TB) and Drive 2 (8TB) as healthy and part of the Pool. I am now adding the first 16TB drive (drive #3) to Storage Pool 1. This has, thus far, be incredible slow. The drive is adding to the storage pool but so far it has taken 16 hours to get it to 47.5 % and Storage Manager says it will take more than another day to finish the addition of this drive. At this rate to add the other three 16TB drive I want it will take 5-6 days or more.

So my question is: is it normal for adding a 16TB drive to an existing storage pool to take 36-48 hours each? If it is OK, I'll be patient, but that seems incredible long. OR have I missed something, a faster way to add a 16TB reformatted drive (exFAT) to the pool?

 

[Lewis]

What drive are you adding, 16TB but which brand model is it?
Maybe it's SMR drive instead CMR so RAID pool rebuild takes loong time on SMR drives..

 

[ColBat]

All my drives are Seagate Ironwolf Pro: two 8TB and five 16TB (1 as a spare).

 

[Lewis]

Then i don't know why is so slow .
I was replacing my 8Tb for 14TB Ironwolfs on DS1817+ and since i was replacing one by one rebuild took about 7 days, i.e. 20-22h per drive (8TB-->14TB).

 

[ColBat]

Never knew or thought about SMR vs CMR. Quick look on line and seems that Seagate Ironwolf are CMR drives only

 

[Lewis]

CMR is better one for NAS so don't worry there (sad face ?), SMR are "evil" in NAS/rebuild speed

 

[ColBat]

Lewis if it took you 20-22hrs for a 14TB I guess I'm in the ballpark with 30-36 hrs for 16TB. I still don't get it. Each drive I am using is a drive I have used before. I have reformatted them (Windows Disk Manager to exFAT) to get rid of all the previous Synology installation. There is nothing on any of the disks because I wanted a clean install of the new SHR array. I make sure they are healthy before I install and add them to the Storage Pool. Just seems like an incredibly slow system given today's technology.

CMR is better one for NAS so don't worry there (sad face ?), SMR are "evil" in NAS/rebuild speed

because I didn't realize it would take so long to do. However, if this ends up with a stable SHR installation that I can start adding my data to, I'll accept the long timeframe to get it done right and not have to do again.

 

[Rusty]

So my question is: is it normal for adding a 16TB drive to an existing storage pool to take 36-48 hours each?

This is more in line with "each rebuild and expansion lasts xxx" than adding a xxTB drive to existing storage. The idea is that the pool needs to recalculate redundancy and expand and the larger the drives and pool the longer it takes. On average, just as an example, a 9TB volume with a single drive replacement (4TB one) takes around 12-15h to complete. So IMHO, you are doing just fine. But yes, it will take days to complete your whole setup.

 

[ColBat]

Thanks Rusty. I guess if I'm going to add three more 16TB drives I may be looking at a week or two to get through it. But if this gives me a stable NAS I take my time and do it right.

This is more in line with "each rebuild and expansion lasts xxx" than adding a xxTB drive to existing storage. The idea is that the pool needs to recalculate redundancy and expand and the larger the drives and pool the longer it takes. On average, just as an example, a 9TB volume with a single drive replacement (4TB one) takes around 12-15h to complete. So IMHO, you are doing just fine. But yes, it will take days to complete your whole setup.

Rusty, I didn't think to ask: Based on what you said, I assume that each new 16TB drive added to the storage pool will take longer to add as the pool has to recalculate redundancy. So the first 16TB drive may take 2 days, the second 16TB drive may take 3 days, the third 16TB drive may take 4 day and the final fourth 16TB drive may take 5-6 days (# of days is just for example. I don't know what type of progression the installation of each drive will take).

So I just want to be clear, the more drives I add to the pool, the longer it will take, right?