On 2013-01-31 04:33, Andrew Wade wrote:
Hi Adam,
Is btrfs mounted relatime? I'm wondering if you're seeing metadata
writes from atime updates. I've got my filesystem mounted noatime to
avoid breaking metadata sharing between subvolumes.
Apologies for the broken threading - I'm not subscribed to the list.
regards,
Andrew
Thank you, thank you!!! Hurray!! That was the problem!! I'm so happy
you've helped me out!!!
After mounting the system with noatime the problem disappeared, like in
magic.
All the writes must have came from the dealyed metadata copy process.
Once all the metadata copy-update was done, file system speed was back
to normal, but once the new day broke out, all the copying business
needed to done again... This in 100% describes all the odd behavior.
In particular apparently the problem had nothing to do with my complex
block device setup, nor with bedup, nor with unison.
Thank you again, Andrew!
P.S. Maybe it is not be decided by me, but this small message about
performance (not even labeled as warning) in
https://btrfs.wiki.kernel.org/index.php/Mount_options IMHO should have
been made more conspicuous, maybe put somewhere when the snapshot
mechanism is described or in FAQ. I'll try to fix it.
--
Adam Ryczkowski
+48505919892 <callto:+48505919892>
Skype:sisteczko <skype:sisteczko>
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
