Replacement disk is too small

[Ardrahan]

I'm trying to replace my older 2T Samsung SSDs after 5 years of use due to smart errors. I added a new 2T WD into an extra bay (sdc) and have had it available as an unassigned drive.

 

However, when I try to assign it to replace one of the Samsung SSDs (sdd) I get a "disk too small" error. (roughly following these steps without the physical drive replacement: https://wiki.unraid.net/Replacing_a_Data_Drive)

 

I've searched the forums a bit but only found references to enabled HPA, which does not seem to be the case for me (eg this thread: 

 

root@Tower:~# hdparm -N /dev/sdc

/dev/sdc:
 max sectors   = 3907029168/3907029168, ACCESSIBLE MAX ADDRESS disabled


root@Tower:~# hdparm -N /dev/sdd

/dev/sdd:
 max sectors   = 3907029168/3907029168, HPA is disabled

Before I tried this I precleared the drive. I also tried clearing it and formatting it, but none of those steps helped.

 

Unraid 6.10.3

 

Any ideas?

 

Thanks,

Chris

[itimpi]

This will be because the latest releases of Unraid start the partition for SSDs on a different start sector (to improve efficiency) so there is slightly less space available.  I think the only way forward would be to use the New Config tool to get the new SSD into the array and then copy across the data from the old SSD.  You might want to wait to see if anyone else has a different idea.

 

Just checking but you do realise that SSDs in the main array cannot be trimmed?   This can lead to their performance degrading over time.

[Ardrahan]

Thanks for the quick reply itimpi. I'm aware of lack of trim, but haven't had any issues over 5 years on my all-SSD array, probably due to my relatively benign usage patterns.

 

Lack of ability to replace my failing data SSD, however, is quite problematic. I have an offline backup unraid instance so I could rebuild if needed. But I would much prefer a drop in replacement capability for my failed data SSDs. Any way for me to get the (perhaps slightly less efficient) start sector behavior back somehow to handle this scenario, unraid devs? 

 

 

[JorgeB]

11 hours ago, Ardrahan said:

Any way for me to get the (perhaps slightly less efficient) start sector behavior back somehow to handle this scenario, unraid devs? 

Only way would be to downgrade Unraid and replace there, then upgrade back, but you'll run into the same issue in the future, I would recommend recreating all the SSDs with the new partition, you can do one by one, once this is done there won't be any further issues with this.

[Ardrahan]

So option A seems to be:
1. add new SSD to array as additional drive. Move all the contents from failing drive to new drive (via mv /mnt/diskX /mnt/diskY). I believe parity is maintained during this step since I'd do it with array started(?)
2. then follow this process to remove failing drive: https://wiki.unraid.net/Shrink_array#The_.22Clear_Drive_Then_Remove_Drive.22_Method
3. I also have SSD parity drive which is also 5 yrs old and may need to be replaced. If that gives me same "disk too small" error.. I wonder if I can add a new SSD as a second parity drive and remove the first? I haven't looked into this yet.

Possible option B: could I just get some 4TB SSDs and replace my 2Ts with 4Ts? Will that just work, because they'd be sufficiently large even with a new start sector? Presumably this would work both for parity and data SSDs?

Edited August 15, 2022 by Ardrahan

[JorgeB]

12 hours ago, Ardrahan said:

1. add new SSD to array as additional drive. Move all the contents from failing drive to new drive (via mv /mnt/diskX /mnt/diskY). I believe parity is maintained during this step since I'd do it with array started(?)

Yes.

 

12 hours ago, Ardrahan said:

I wonder if I can add a new SSD as a second parity drive and remove the first? I haven't looked into this yet.

You can.

 

12 hours ago, Ardrahan said:

ossible option B: could I just get some 4TB SSDs and replace my 2Ts with 4Ts? Will that just work, because they'd be sufficiently large even with a new start sector? Presumably this would work both for parity and data SSDs?

Yes, obviously parity would need to be done first.