I noticed something odd when I booted rc1 on my btrfs test box.. First I tried updating my git tree.. $ gp error: cannot open .git/FETCH_HEAD: Input/output error $ gp remote: Counting objects: 5101, done. remote: Compressing objects: 100% (546/546), done. remote: Total 3764 (delta 3233), reused 3738 (delta 3208) Receiving objects: 100% (3764/3764), 783.19 KiB | 195 KiB/s, done. Resolving deltas: 100% (3233/3233), completed with 831 local objects. fatal: fsync error on ''.git/objects/pack/tmp_pack_gq3edw'': Input/output error fatal: index-pack failed uh-oh. I looked in dmesg, nothing out of the ordinary (disks dying etc). But anything that does IO seems to have serious issues.. $ fsx foo truncating to largest ever: 0x13e76 truncating to largest ever: 0x2e52c ftruncate1: 2e52c dotruncate: ftruncate: Input/output error Segmentation fault (core dumped) 3.3 is fine. Thoughts ? Dave