quoted

This is correct, but I should note that I did not add it as
write-mostly just
because it's an older drive, but because it is my normal set-up for
md3:
a RAID1 mirror of a fast SSD (sdf) and a write-mostly HDD (sdg in
this case).

Again, I find it odd that sdg while rebuilding is reading any sectors.
The read errors are coming from sdg. That it's also write-mostly
enhances the mystery why sdg is being read from.

I would fail the HDD, and btrfs scrub the array which in effect should
scrub only sdf. And it may also need an offline btrfsck. The source
(sdf) is already suspect because of btrfs not finding checksums where
it was expecting to find them, and then on top of this you're getting
sdg producing bad sector errors on reads.

Have you done a SMART check of sdg? smartctl -H first, then smartctl -t short, then smartctl -t long (with smartctl -H between them)

You might also consider posting the configuration and full dmesg to
the btrfs list. I'm curious what btrfs developers think of this
configuration.

It's not btrfs - it's below that.

Vennlige hilsener / Best regards

roy
--
Roy Sigurd Karlsbakk
(+47) 98013356
roy@karlsbakk.net
http://blogg.karlsbakk.net/
GPG Public key: http://karlsbakk.net/roysigurdkarlsbakk.pubkey.txt
--
I all pedagogikk er det essensielt at pensum presenteres intelligibelt. Det er et elementært imperativ for alle pedagoger å unngå eksessiv anvendelse av idiomer med xenotyp etymologi. I de fleste tilfeller eksisterer adekvate og relevante synonymer på norsk.
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html