(solved) Rebuild slowed to 2MB/s


tazman

Recommended Posts

Hi,

 

I am rebuiling my Disk 11 (old 3TB, new 4TB) at the moment. The rebuild began last night with the expected ~80MB/s and was due to complete in 13 or so hours.

 

When I looked at that status this morning the rebuild was at 50% but the speed dropped to ~2MB/s with a time to complete in 8 days.

 

I never had this before and wonder what to do about it.

 

syslog is free of any related error as far as I can tell. The SMART report of the new drive does not show anything either.

 

I am attaching the diagnostics file and welcome your kind advice on how to proceed.

 

Thanks!

 

Tazman

ss-diagnostics-20191015-0528.zip

Edited by tazman
spelling, solved
Link to comment
34 minutes ago, itimpi said:

That is not going to help much as the rebuild cannot happen faster than the slowest disk.

 

Using something like the DiskSpeed docker container would be one way to check out the performance of individual drives.

I ran DiskSpeed a few month ago, it's very insightful. The now to be replaced Disk 11 was actually the slowest in the pack.

 

So do I understand you right that most likely one of the other disks might be slowing down the entire process?

Link to comment
3 minutes ago, tazman said:

So do I understand you right that most likely one of the other disks might be slowing down the entire process?

That was what I was thinking.   It might be worth making a note of the current point reached as that could act as a guide to which section of the DiskSpeed graphs are most likely to be relevant.

Link to comment

The extended SMART test on the partity 2 drive completed without errors. I then restarted the rebuild and it continued with the normal speed. The read speeds which showed around 4.5MB in the picture above increased to ~75 and the write speed to ~65.

 

After the rebuild was complete I ran DiskSpeed again and it did complete for all drives.

 

Although I obviously like the fact, that it fixed itself, I will keep Parity 2 on close watch.

Edited by tazman
added new read speeds
Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.