Hi All,

In Googling how to throttle rebuild I found some old post about speed_limit_max but some indications that this has been depracated. When I try I get this:

root@Tower:~# echo 5000 > /proc/sys/dev/raid/speed_limit_max
-bash: /proc/sys/dev/raid/speed_limit_max: No such file or directory



My system is older it's crashing when I try to rebuild data on a larger drive I installed. I'd like to throttle it way down, even if it means the rebuild takes 4-5 days. Thoughts?

Not clear it would help. Better if you figure out why it's crashing.

Attach Diagnostics ZIP to your NEXT post in this thread.

Site says, but when system locks up, I get locked out of ssh....so a hard reboot is required.

WebGUI not available

Access via SSH, telnet, or direct console to run the diagnostics command. The zip file saves to /boot/logs.

Always capture diagnostics before rebooting to keep logs intact.

Post diagnostics now, then setup syslog server to capture syslog for posting after crash.

Diagnostics attached. Data rebuild is going on now. It's taxing the system but, this server has been running for quite some time for me and it does what I need it to do. I just need to get my parity back so my data is safe. This has always happened during rebuilds, it crashes pretty quickly if I try to access my media while rebuild is happening. I let it run 36 hours (estimate was 24-26 hours for rebuild) and it failed for me (despite the fact that I left it alone for a day and a half).

tower-diagnostics-20260402-1935.zip

11 hours ago, trurl said:

syslog server to capture syslog for posting after crash.

Post a screenshot of those settings.

Nothing obvious in those diagnostics. Might be useful to install Fix Common Problems plugin.

I can 100% guarantee a crash if I watch something from the unraid server as I rebuild the data disk. It'll crash within minutes. I'm hesitant to purposefully do it as I try to hobble through a full rebuild.....

Also, the server is stored in an electronic closet not with a monitor, for me to get it onto a monitor I have to take it down and put it in my living room. I'd love to figure this out, just not sure I have the time immediately and right now the goal is really the rebuild if I can get it done.

On 4/3/2026 at 7:00 AM, trurl said:

Nothing obvious in those diagnostics. Might be useful to install Fix Common Problems plugin.

Installed and ran. Didn't find any problems.

Will it crash if you do parity check while watching something?

Trying to read or write large amounts of data at the same time parity check or rebuild is happening will affect performance of reading or writing, and will affect performance of parity check or rebuild. That is simply due to disks needing to seek a lot as it tries to go from one part of the disks for accessing data, and another part of a disks for parity check or rebuild.

Parity Check Tuning Plugin will allow you to schedule parity checks/rebuilds to work during idle time.