I've been trying to get a handle on where my Btrfs partition would run out of room, and I'm reaching the 'no space left' point earlier than I was expecting. I'm running the btrfs-unstable.git version as of commit 035fe03a Thu, 28 Jan 2010 21:20:39 (Btrfs: check total number of devices when removing missing) back-ported to a 2.6.32 kernel. Also, I've manually added Josef Bacik's 'btrfsctl -i' patches to get more information about the state when full. I'm using a single 13.4GB partition as a root partition for a Sabayon Linux system. With the btrfs file system ~59% full, I booted to another partition, and filled the remainder of the space using 'dd' (dd if=/dev/urandom of=/<path-to-btrfs-mounted-partition>/randomdata bs=1024k) to see where I'd get a full-disk error. A btrfs 'no space left' error is received with the 'df' command showing only 81% full. 'df -T' reports: Filesystem Type 1K-blocks Used Available Use% Mounted on /dev/sda5 btrfs 14008648 11314552 2694096 81% /mnt/sabayon-btrfs The dmesg disk full error reported: [ 1606.386085] no space left, need 1048576, 89128960 delalloc bytes, 10639556608 bytes_used, 3981312 bytes_reserved, 0 bytes_pinned, 0 bytes_readonly, 0 may use 10733551616 total Josef Bacik's 'btrfsctl -i' command reported: # btrfsctl -i /mnt/sabayon-btrfs/ Metadata, DUP: total=1.67GB, used=813.89MB System, DUP: total=8.00MB, used=4.00KB Data: total=10.00GB, used=10.00GB Metadata: total=8.00MB, used=0.00 System: total=4.00MB, used=0.00 operation complete Btrfs Btrfs v0.19 Using 'btrfsctl -i', I'm still having trouble closing the loop on disk utilization. 10.00 GB Data + 1.67 GB Metadata = 11.67GB. Since this is a 13.4GB partition, I'm still missing ~1.7GB, based on the 'btrfsctl -i' reporting. Is 1.67 GB reserved for Metadata about what might be expected for a messy root partition with ~10GB of files? -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
