our python-based program crashed with File "/home/yoh/proj/datalad/datalad/venv-tests/local/lib/python2.7/site-packages/gitdb/stream.py", line 695, in write os.write(self._fd, data) OSError: [Errno 28] No space left on device
but as far as I could see there still should be both data and meta data space left: $> sudo btrfs fi df $PWD Data, RAID0: total=33.55TiB, used=30.56TiB System, RAID1: total=32.00MiB, used=1.81MiB Metadata, RAID1: total=83.00GiB, used=64.81GiB GlobalReserve, single: total=512.00MiB, used=0.00B $> sudo btrfs fi usage $PWD Overall: Device size: 43.66TiB Device allocated: 33.71TiB Device unallocated: 9.95TiB Device missing: 0.00B Used: 30.69TiB Free (estimated): 12.94TiB (min: 7.96TiB) Data ratio: 1.00 Metadata ratio: 2.00 Global reserve: 512.00MiB (used: 0.00B) Data,RAID0: Size:33.55TiB, Used:30.56TiB /dev/md10 8.39TiB /dev/md11 8.39TiB /dev/md12 8.39TiB /dev/md13 8.39TiB Metadata,RAID1: Size:83.00GiB, Used:64.81GiB /dev/md10 41.00GiB /dev/md11 42.00GiB /dev/md12 41.00GiB /dev/md13 42.00GiB System,RAID1: Size:32.00MiB, Used:1.81MiB /dev/md10 32.00MiB /dev/md12 32.00MiB Unallocated: /dev/md10 2.49TiB /dev/md11 2.49TiB /dev/md12 2.49TiB /dev/md13 2.49TiB (so it is RAID0 for data sitting on top of software RAID5s) I am running Debian jessie with custom built kernel Linux smaug 4.9.0-rc2+ #3 SMP Fri Oct 28 20:59:01 EDT 2016 x86_64 GNU/Linux btrfs-tools were 4.6.1-1~bpo8+1 , FWIW upgraded to 4.7.3-1~bpo8+1 I do have a fair number of subvolumes (794! snapshots + used by docker) so what could be the catch -- currently can't even touch a new file (can touch existing ;-/ )? meanwhile removing some snapshots, syncing and rebooting in attempt to mitigate not usable server looking at the logs, I see that there were some traces logged a day ago: ... May 17 01:47:41 smaug kernel: INFO: task kworker/u33:15:318164 blocked for more than 120 seconds. May 17 01:47:41 smaug kernel: Tainted: G I L 4.9.0-rc2+ #3 May 17 01:47:41 smaug kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. May 17 01:47:41 smaug kernel: kworker/u33:15 D ffffffff815e6fd3 0 318164 2 0x00000000 May 17 01:47:41 smaug kernel: Workqueue: writeback wb_workfn (flush-btrfs-1) May 17 01:47:41 smaug kernel: ffff88102dba3400 0000000000000000 ffff8810390741c0 ffff88103fc98740 May 17 01:47:41 smaug kernel: ffff881036640e80 ffffc9002af334e8 ffffffff815e6fd3 0000000000000000 May 17 01:47:41 smaug kernel: ffff881038800668 ffffc9002af33540 ffff881036640e80 ffff881038800668 May 17 01:47:41 smaug kernel: Call Trace: May 17 01:47:41 smaug kernel: [<ffffffff815e6fd3>] ? __schedule+0x1a3/0x670 May 17 01:47:41 smaug kernel: [<ffffffff815e74d2>] ? schedule+0x32/0x80 May 17 01:47:41 smaug kernel: [<ffffffffa030d180>] ? raid5_get_active_stripe+0x4f0/0x670 [raid456] May 17 01:47:41 smaug kernel: [<ffffffff810bfc30>] ? wake_up_atomic_t+0x30/0x30 May 17 01:47:41 smaug kernel: [<ffffffffa030d48d>] ? raid5_make_request+0x18d/0xc40 [raid456] May 17 01:47:41 smaug kernel: [<ffffffff810bfc30>] ? wake_up_atomic_t+0x30/0x30 May 17 01:47:41 smaug kernel: [<ffffffffa00f2f85>] ? md_make_request+0xf5/0x230 [md_mod] May 17 01:47:41 smaug kernel: [<ffffffff812f2566>] ? generic_make_request+0x106/0x1f0 May 17 01:47:41 smaug kernel: [<ffffffff812f26c6>] ? submit_bio+0x76/0x150 May 17 01:47:41 smaug kernel: [<ffffffffa03a535e>] ? btrfs_map_bio+0x10e/0x370 [btrfs] May 17 01:47:41 smaug kernel: [<ffffffffa0377f18>] ? btrfs_submit_bio_hook+0xb8/0x190 [btrfs] May 17 01:47:41 smaug kernel: [<ffffffffa0393746>] ? submit_one_bio+0x66/0x90 [btrfs] May 17 01:47:41 smaug kernel: [<ffffffffa0397798>] ? submit_extent_page+0x138/0x310 [btrfs] May 17 01:47:41 smaug kernel: [<ffffffffa0397500>] ? end_extent_writepage+0x80/0x80 [btrfs] May 17 01:47:41 smaug kernel: [<ffffffffa0397d90>] ? __extent_writepage_io+0x420/0x4e0 [btrfs] May 17 01:47:41 smaug kernel: [<ffffffffa0397500>] ? end_extent_writepage+0x80/0x80 [btrfs] May 17 01:47:41 smaug kernel: [<ffffffffa0398059>] ? __extent_writepage+0x209/0x340 [btrfs] May 17 01:47:41 smaug kernel: [<ffffffffa0398412>] ? extent_write_cache_pages.isra.40.constprop.51+0x282/0x380 [btrfs] May 17 01:47:41 smaug kernel: [<ffffffffa039a31d>] ? extent_writepages+0x5d/0x90 [btrfs] May 17 01:47:41 smaug kernel: [<ffffffffa037a420>] ? btrfs_set_bit_hook+0x210/0x210 [btrfs] May 17 01:47:41 smaug kernel: [<ffffffff81230d6d>] ? __writeback_single_inode+0x3d/0x330 May 17 01:47:41 smaug kernel: [<ffffffff8123152d>] ? writeback_sb_inodes+0x23d/0x470 May 17 01:47:41 smaug kernel: [<ffffffff812317e7>] ? __writeback_inodes_wb+0x87/0xb0 May 17 01:47:41 smaug kernel: [<ffffffff81231b62>] ? wb_writeback+0x282/0x310 May 17 01:47:41 smaug kernel: [<ffffffff812324d8>] ? wb_workfn+0x2b8/0x3e0 May 17 01:47:41 smaug kernel: [<ffffffff810968bb>] ? process_one_work+0x14b/0x410 May 17 01:47:41 smaug kernel: [<ffffffff81097375>] ? worker_thread+0x65/0x4a0 May 17 01:47:41 smaug kernel: [<ffffffff81097310>] ? rescuer_thread+0x340/0x340 May 17 01:47:41 smaug kernel: [<ffffffff8109c670>] ? kthread+0xe0/0x100 May 17 01:47:41 smaug kernel: [<ffffffff8102b76b>] ? __switch_to+0x2bb/0x700 May 17 01:47:41 smaug kernel: [<ffffffff8109c590>] ? kthread_park+0x60/0x60 May 17 01:47:41 smaug kernel: [<ffffffff815ec0b5>] ? ret_from_fork+0x25/0x30 May 17 01:47:59 smaug kernel: NMI watchdog: BUG: soft lockup - CPU#5 stuck for 23s! [kswapd1:126] ... May 17 02:03:08 smaug kernel: NMI watchdog: BUG: soft lockup - CPU#13 stuck for 23s! [kswapd1:126] May 17 02:03:08 smaug kernel: Modules linked in: cpufreq_userspace cpufreq_conservative cpufreq_powersave xt_pkttype nf_log_ipv4 nf_log_common xt_tcpudp ip6table_mangle iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat xt_TCPMSS xt_LOG ipt_REJECT nf_reject_ipv4 iptable_mangle xt_multiport xt_state xt_limit xt_conntrack nf_conntrack_ftp nf_conntrack ip6table_filter ip6_tables iptable_filter ip_tables x_tables nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc binfmt_misc ipmi_watchdog iTCO_wdt iTCO_vendor_support intel_rapl sb_edac edac_core x86_pkg_temp_thermal coretemp kvm_intel kvm ast irqbypass ttm crct10dif_pclmul drm_kms_helper crc32_pclmul ghash_clmulni_intel snd_pcm drm snd_timer snd i2c_algo_bit soundcore aesni_intel aes_x86_64 lrw mei_me gf128mul joydev pcspkr evdev glue_helperss scsi_transport_sas ahci libahci xhci_pci ehci_pci libata xhci_hcd ehci_hcd usbcore ixgbe scsi_mod dca ptp pps_core mdio fjes name: Supermicro X10DRi/X10DRI-T, BIOS 1.0b 09/17/2014 May 17 02:03:08 smaug kernel: task: ffff8810365c8f40 task.stack: ffffc9000d26c000 May 17 02:03:08 smaug kernel: RIP: 0010:[<ffffffff8119731c>] [<ffffffff8119731c>] shrink_active_list+0x14c/0x360 May 17 02:03:08 smaug kernel: RSP: 0018:ffffc9000d26fbc0 EFLAGS: 00000206 May 17 02:03:08 smaug kernel: RAX: 0000000000000064 RBX: ffffc9000d26fe01 RCX: 000000000001bc87 May 17 02:03:08 smaug kernel: RDX: 0000000000463781 RSI: 0000000000000007 RDI: ffff88207fffc800 May 17 02:03:08 smaug kernel: RBP: ffffc9000d26fc10 R08: 000000000001bc80 R09: 0000000000000003 May 17 02:03:08 smaug kernel: R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 May 17 02:03:08 smaug kernel: R13: ffffc9000d26fe58 R14: ffffc9000d26fc30 R15: ffff88203936d200 May 17 02:03:08 smaug kernel: FS: 0000000000000000(0000) GS:ffff88207fd40000(0000) knlGS:0000000000000000 May 17 02:03:08 smaug kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 May 17 02:03:08 smaug kernel: CR2: 00002b64de150000 CR3: 0000000001a07000 CR4: 00000000001406e0 May 17 02:03:08 smaug kernel: Stack: May 17 02:03:08 smaug kernel: ffff881600000000 ffff882000000003 ffff88207fff9000 ffff88203936d200 May 17 02:03:08 smaug kernel: ffff88207fffc800 0000000000000000 0000000600000003 ffff88203936d208 May 17 02:03:08 smaug kernel: 0000000000463781 0000000000000000 ffffc9000d26fc10 ffffc9000d26fc10 May 17 02:03:08 smaug kernel: Call Trace: May 17 02:03:08 smaug kernel: [<ffffffff81197b3f>] ? shrink_node_memcg+0x60f/0x780 May 17 02:03:08 smaug kernel: [<ffffffff81197d92>] ? shrink_node+0xe2/0x320 May 17 02:03:08 smaug kernel: [<ffffffff81198dd8>] ? kswapd+0x318/0x700 May 17 02:03:08 smaug kernel: [<ffffffff81198ac0>] ? mem_cgroup_shrink_node+0x180/0x180 May 17 02:03:08 smaug kernel: [<ffffffff8109c670>] ? kthread+0xe0/0x100 May 17 02:03:08 smaug kernel: [<ffffffff8102b76b>] ? __switch_to+0x2bb/0x700 May 17 02:03:08 smaug kernel: [<ffffffff8109c590>] ? kthread_park+0x60/0x60 May 17 02:03:08 smaug kernel: [<ffffffff815ec0b5>] ? ret_from_fork+0x25/0x30 May 17 02:03:08 smaug kernel: Code: 38 4c 01 66 60 49 83 7d 18 00 0f 84 0d 02 00 00 65 48 01 15 4f d3 e7 7e 48 8b 7c 24 20 c6 07 00 0f 1f 40 00 fb 66 0f 1f 44 00 00 <45> 31 e4 48 8b 44 24 50 48 39 c5 0f 84 a3 00 00 00 e8 9e 03 45 not sure if anyhow related but somewhat strange is that swap is not used a tiny bit: $> free total used free shared buffers cached Mem: 131934232 124357760 7576472 3816 999100 112204512 -/+ buffers/cache: 11154148 120780084 Swap: 140623856 0 140623856 $> cat /proc/swaps Filename Type Size Used Priority /dev/sdp6 partition 39062524 0 -1 /dev/sdp5 partition 31249404 0 -2 /dev/sdo6 partition 39062524 0 -4 /dev/sdo5 partition 31249404 0 -3 P.S. Please CC me in replies -- Yaroslav O. Halchenko Center for Open Neuroscience http://centerforopenneuroscience.org Dartmouth College, 419 Moore Hall, Hinman Box 6207, Hanover, NH 03755 Phone: +1 (603) 646-9834 Fax: +1 (603) 646-1419 WWW: http://www.linkedin.com/in/yarik -- 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