Hello, I am looking for some clarification on TRIM / SSD maintenance. The wiki [1] suggests periodic fstrim, but fstrim does not discard unallocated blocks[2]. Which makes sense, given that mkfs issues a device wide trim, so they shouldn't have data. But it seems like both a balance, and a pending patch ( 47ab2a6 Btrfs: remove empty block groups automatically ) can deallocate block groups without TRIM, leading to the SSD retaining data it doesn't need to. Is there a bitter way to trigger a more thorough discard than fallocate, rm, fstrim, balance -dusage=0 ? And are there plans to support trimming unallocated space, or is this not possible with current FS format? Thank you, Noah [1] https://btrfs.wiki.kernel.org/index.php/FAQ#Does_Btrfs_support_TRIM.2Fdiscard.3F [2] https://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg14195.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html