> [ ... ] I ran "btrfs balance" and then it started working > correctly again. It seems that a btrfs filesystem if left > alone will eventually get fragmented enough that it rejects > writes [ ... ]
Free space will get fragmented, because Btrfs has a 2-level allocator scheme (chunks within devices and leaves within chunks). The issue is "free space" vs. "unallocated chunks". > Is this a known issue? https://btrfs.wiki.kernel.org/index.php/Problem_FAQ#I_get_.22No_space_left_on_device.22_errors.2C_but_df_says_I.27ve_got_lots_of_space https://btrfs.wiki.kernel.org/index.php/FAQ#if_your_device_is_large_.28.3E16GiB.29 https://btrfs.wiki.kernel.org/index.php/FAQ#Understanding_free_space.2C_using_the_new_tools https://btrfs.wiki.kernel.org/index.php/FAQ#Why_is_free_space_so_complicated.3F https://btrfs.wiki.kernel.org/index.php/FAQ#What_does_.22balance.22_do.3F That problem is particularly frequent with the 'ssd' mount option which probably should never be used: https://btrfs.wiki.kernel.org/index.php/Gotchas#The_ssd_mount_option -- 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
