Re: mdadm resync causes stable system to crash every 2 or 3 hours

Roman Mamedov
2021-09-07T07:57:34Z

On Mon, 6 Sep 2021 20:44:31 -0400
Ryan Patterson <ryan.goat@gmail.com> wrote:

> My file server is usually very stable. The past week I had two mdadm
> arrays that required recync operations.
> * newly created raid6 array (14 x 16TB seagate exos)
> * existing raid 6 array, after a reboot resync on hot spare (14 x 4TB
> seagate barracuda)
>
> During both resync operations (they ran one at a time) the system
> would routinely experience a major error and require a hard reboot,
> every two or three hours. I saw several errors, such as:
> * kernel watchdog soft lockups [md127_raid6:364]
> * general protection faults (I have a few saved with the full exception stack)
> * exceptions in iommu routines (again I have the full error with
> exception stack saved)
> * full system lockup

So in other words the server is very stable, unless asked to do full-speed
reads from all disks at the same time.

I'd suggest to check or improve cooling on the HBA cards, and then try a
different PSU.

> I doubt there is a bug in mdadm that caused this behavior. But it was
> very predictable and repeatable while the resync operations were in
> progress.
>
> How can I avoid these errors the next time I have an array in need of a resync?
>
> OS: debian 11 bullseye
> kernel: 5.10.0-8-amd64 #1 SMP Debian 5.10.46-4 (2021-08-03)
> mdadm: v4.1 - 2018-10-01
> sata HBA: 3 x LSI SAS 9201-16i
> _____________
> Ryan Patterson
> May the wings of liberty never lose a feather.

--
With respect,
Roman