Re: How to salvage a degraded mdadm RAID1 with as little data loss as possible?

On 2026-06-21, Paul Leiber wrote:

> I just noticed that I didn't manage to make clear that (1) I don't think that
> there is one specific failed partition, but that both partitions containing
> databases seem to work, but not at the same time, and that (2) I want to keep
> the data on the seemingly failed device.
[...]

I used raid for tens of years and never had the problem you described. So
I believe it should come from something else than raid failure. raid
duplicates data on both partitions. If you don't have a failed partition
the duplication is done transparently and quickly (<second). When a
partition fails you can add a new and clean partition and the original
one, the partition still in raid, is synchronized into it. As others told
you you should use smartd to monitor your disks.