On Mon, Dec 3, 2018 at 10:44 PM Tomasz Chmielewski <man...@wpkg.org> wrote: > > I'm trying to use btrfs on an external USB drive, without much success. > > When the drive is connected for 2-3+ days, the filesystem gets remounted > readonly, with BTRFS saying "IO failure": > > [77760.444607] BTRFS error (device sdb1): bad tree block start, want > 378372096 have 0 > [77760.550933] BTRFS error (device sdb1): bad tree block start, want > 378372096 have 0 > [77760.550972] BTRFS: error (device sdb1) in __btrfs_free_extent:6804: > errno=-5 IO failure > [77760.550979] BTRFS info (device sdb1): forced readonly > [77760.551003] BTRFS: error (device sdb1) in > btrfs_run_delayed_refs:2935: errno=-5 IO failure > [77760.553223] BTRFS error (device sdb1): pending csums is 4096 > > > Note that there are no other kernel messages (i.e. that would indicate a > problem with disk, cable disconnection etc.). > > The load on the drive itself can be quite heavy at times (i.e. 100% IO > for 1-2 h and more) - can it contribute to the problem (i.e. btrfs > thinks there is some timeout somewhere)? > > Running 4.19.6 right now, but was experiencing the issue also with 4.18 > kernels. > > > > # btrfs device stats /data > [/dev/sda1].write_io_errs 0 > [/dev/sda1].read_io_errs 0 > [/dev/sda1].flush_io_errs 0 > [/dev/sda1].corruption_errs 0 > [/dev/sda1].generation_errs 0
Hard to say without a complete dmesg; but errno=-5 IO failure is pretty much some kind of hardware problem in my experience. I haven't seen it be a bug. -- Chris Murphy
