Failed to create IMU directory during holistic recording

finn

Hi,
I am experiencing issues when recording IMU data using holistic recording. It looks as if the IMU sensor does not start (no data is printed) and thereby no data can be written.

[depthai] [error] Record: Failed to create tar file: filesystem error: cannot get file size: No such file or directory [/home/xy/output/2026-01-05T131454/1944301081E8A62E00_b_IMU.mcap]

When disabling IMU (only recordings camera data) no errors are observed.

I am using:

depthai 3.1.0
Oak-D Pro PoE
IMU Firmware 3.9.9
BNO086

Code:

dai:: Pipeline pipeline(device); auto camA = pipeline.create<dai::node::Camera>()->build(dai::CameraBoardSocket::CAM_A);
auto* camAOut = camA->requestOutput({600, 400});
auto camB = pipeline.create<dai::node::Camera>()->build(dai::CameraBoardSocket::CAM_B);
auto* camBOut = camB->requestOutput({600, 400});
auto camC = pipeline.create<dai::node::Camera>()->build(dai::CameraBoardSocket::CAM_C);
auto* camCOut = camC->requestOutput({600, 400});
std::unordered_map<std::string, std::shared_ptr<dai::MessageQueue>> q;
q.emplace("A", camAOut->createOutputQueue(1));
q.emplace("B", camBOut->createOutputQueue(1));
q.emplace("C", camCOut->createOutputQueue(1));
auto imu = pipeline.create<dai::node::IMU>();
// enable ACCELEROMETER_RAW at 500 hz rate
imu->enableIMUSensor(dai::IMUSensor::ACCELEROMETER, 500);
// enable GYROSCOPE_RAW at 400 hz rate
imu->enableIMUSensor(dai::IMUSensor::GYROSCOPE_CALIBRATED, 400);
imu->setBatchReportThreshold(100);
auto imu_q = imu->out.createOutputQueue();
dai::RecordConfig config;
config.outputDir = directory;
config.videoEncoding.enabled = true; // Use video encoding
config.videoEncoding.bitrate = 0; // Automatic config.videoEncoding.profile = dai::VideoEncoderProperties:: Profile::H264_MAIN; pipeline.enableHolisticRecord(config); pipeline.start(); std::cout << "pipeline started \n"; auto start = std::chrono::steady_clock::now();
auto cur = start;
int ping_count = 0;
try
{
while (std::chrono::steady_clock::now() - start < std::chrono::seconds(15))
{
for (const auto &[name, que] : q)
{
que->tryGet<dai::ImgFrame>();
}
if (std::chrono::steady_clock::now() - cur > std::chrono::seconds(1)) {
std::cout << ping_count << "\n";
cur = std::chrono::steady_clock::now();
ping_count++;
}
auto imu_data = imu_q->tryGet<dai::IMUData>();
if (imu_data != nullptr) {
for (const auto &package : imu_data->packets) {
std::cout << package.gyroscope.x << " " << package.gyroscope.y << " " << package.gyroscope.z << "\n";
}
}
std::this_thread::sleep_for(std::chrono::milliseconds(1));
}
} catch (const std::exception &e)
{
std::cout << e.what() << "\n";
}
pipeline.stop();

OskarSonc

Hey @finn - The tar error is just a symptom - holistic record expects to write *_IMU.mcap, but since the IMU stream never outputs any packets that file never gets created, so bundling fails.

Can you try switching to RAW IMU streams + smaller batching, and verify you receive at least one packet?

imu->enableIMUSensor(dai::IMUSensor::ACCELEROMETER_RAW, 480);
imu->enableIMUSensor(dai::IMUSensor::GYROSCOPE_RAW, 400);
imu->setBatchReportThreshold(1);
imu->setMaxBatchReports(10);

For a quick sanity check, do one blocking read once to confirm anything is flowing.

Also, please try our pre-made IMU example to isolate the problem.

Thanks,
Oskar

finn

Hi @OskarSonc
thanks for the quick reply. I tried running this example. The problem seems to arise from a crashing IMU. I receive a couple of IMU samples before no more data is received, e.g. the get-call blocks the loop without any error being thrown. I tried increasing max queue sizes, decreasing imu sample rates and using non-blocking queues, no success.

Here is the last debug output right after the IMU crash:
Latency [ms]: 5.000000

Accelerometer [m/s^2]: x: -0.248997 y: -10.333375 z: -0.450110

Gyroscope timestamp: 62215139004590

Gyroscope [rad/s]: x: 0.007457 y: -0.009587 z: -0.012783

[1944301081E8A62E00] [169.254.1.222] [50.345] [system] [info] Memory Usage - DDR: 0.13 / 333.26 MiB, CMX: 2.07 / 2.50 MiB, LeonOS Heap: 27.09 / 81.17 MiB, LeonRT Heap: 2.93 / 39.20 MiB / NOC ddr: 60 MB/s

[1944301081E8A62E00] [169.254.1.222] [50.345] [system] [info] Temperatures - Average: 41.49C, CSS: 43.50C, MSS 40.74C, UPA: 40.51C, DSS: 41.20C

[1944301081E8A62E00] [169.254.1.222] [50.345] [system] [info] Cpu Usage - LeonOS 35.94%, LeonRT: 0.05%

Any ideas? Thanks, Finn

OskarSonc

Hey finn - the device logs look healthy (no resource/thermal issue), so this looks like the IMU stream itself stalling. Can you update to the latest dai version 3.2.1 and run the same example as before with DEPTHAI_LEVEL=debug and share logs?

Thanks,
Oskar

finn

Sure @OskarSonc

[2026-01-07 13:27:22.771] [depthai] [info] Environment variable DEPTHAI_DEBUG is not set. Using default value: ''
[2026-01-07 13:27:22.771] [depthai] [info] Environment variable DEPTHAI_LIBUSB_ANDROID_JAVAVM is not set. Using default value: ''
[2026-01-07 13:27:22.771] [depthai] [debug] Library information - version: 3.1.0, commit:  from , build: 2025-10-15 20:43:36 +0000, libusb enabled: true
[2026-01-07 13:27:22.792] [depthai] [info] Environment variable DEPTHAI_PROFILING is not set. Using default value: ''
[2026-01-07 13:27:22.792] [depthai] [info] Environment variable XLINK_LEVEL is not set. Using default value: ''
[2026-01-07 13:27:22.792] [depthai] [debug] Initialize - finished
[2026-01-07 13:27:22.797] [host] [debug] Found an actual device by given DeviceInfo: DeviceInfo(name=169.254.1.222, deviceId=1944301081E8A62E00, X_LINK_BOOTLOADER, X_LINK_TCP_IP, X_LINK_MYRIAD_X, X_LINK_SUCCESS)
[2026-01-07 13:27:22.797] [host] [debug] Device - OpenVINO version: universal
[2026-01-07 13:27:22.797] [depthai] [info] Environment variable DEPTHAI_WATCHDOG is not set. Using default value: ''
[2026-01-07 13:27:22.797] [depthai] [info] Environment variable DEPTHAI_WATCHDOG_INITIAL_DELAY is not set. Using default value: ''
[1944301081E8A62E00] [169.254.1.222] [1767792442.797] [host] [debug] Device - BoardConfig: {"camera":[],"defaultImuExtr":{},"emmc":null,"gpio":[],"imu":null,"logDevicePrints":null,"logPath":null,"logSizeMax":null,"logVerbosity":null,"network":{"mtu":0,"xlinkTcpNoDelay":true},"nonExclusiveMode":false,"pcieInternalClock":null,"sysctl":[],"uart":[],"usb":{"flashBootedPid":63037,"flashBootedVid":999,"manufacturer":"","maxSpeed":4,"pid":63035,"productName":"","vid":999},"usb3PhyInternalClock":null,"uvc":null,"watchdogInitialDelayMs":null,"watchdogTimeoutMs":null} 
libnop:
0000: b9 13 b9 07 81 e7 03 81 3b f6 81 e7 03 81 3d f6 04 bd 00 bd 00 b9 02 00 01 ba 00 be be bb 00 bb
0020: 00 be be be be be be be 00 bb 00 be be bb 00
[2026-01-07 13:27:23.014] [depthai] [debug] Resources - Archive 'depthai-bootloader-fwp-0.0.28.tar.xz' open: 5ms, archive read: 236ms
[2026-01-07 13:27:24.149] [depthai] [debug] Resources - Archive 'depthai-device-fwp-0ada9b9800478cf2c7056cea5c2bab2c8f6a2cbd.tar.xz' open: 5ms, archive read: 1370ms
[2026-01-07 13:27:24.149] [depthai] [info] Environment variable DEPTHAI_DEVICE_BINARY is not set. Using default value: ''
[2026-01-07 13:27:24.197] [depthai] [info] Environment variable DEPTHAI_CONNECT_TIMEOUT is not set. Using default value: ''
[2026-01-07 13:27:24.197] [depthai] [info] Environment variable DEPTHAI_BOOTUP_TIMEOUT is not set. Using default value: ''
[2026-01-07 13:27:24.197] [depthai] [debug] Searching for booted device: DeviceInfo(name=169.254.1.222, deviceId=1944301081E8A62E00, X_LINK_BOOTLOADER, X_LINK_TCP_IP, X_LINK_MYRIAD_X, X_LINK_SUCCESS), name used as hint only
[2026-01-07 13:27:24.219] [depthai] [debug] Connected bootloader version 0.0.28
[1944301081E8A62E00] [169.254.1.222] [1767792445.276] [host] [debug] Booting FW with Bootloader. Version 0.0.28, Time taken: 1056ms
[2026-01-07 13:27:25.277] [depthai] [debug] DeviceBootloader about to be closed...
[2026-01-07 13:27:25.277] [depthai] [debug] XLinkResetRemote of linkId: (0)
[2026-01-07 13:27:26.325] [depthai] [debug] DeviceBootloader closed, 1048
[2026-01-07 13:27:26.343] [depthai] [debug] Searching for booted device: DeviceInfo(name=169.254.1.222, deviceId=1944301081E8A62E00, X_LINK_BOOTED, X_LINK_TCP_IP, X_LINK_MYRIAD_X, X_LINK_SUCCESS), name used as hint only
[2026-01-07 13:27:37.316] [depthai] [info] Environment variable DEPTHAI_CRASHDUMP is not set. Using default value: ''
[1944301081E8A62E00] [169.254.1.222] [11.480] [system] [info] Memory Usage - DDR: 0.12 / 333.26 MiB, CMX: 2.04 / 2.50 MiB, LeonOS Heap: 25.66 / 81.17 MiB, LeonRT Heap: 2.89 / 39.20 MiB / NOC ddr: 0 MB/s
[1944301081E8A62E00] [169.254.1.222] [11.480] [system] [info] Temperatures - Average: 41.08C, CSS: 43.27C, MSS 40.28C, UPA: 40.28C, DSS: 40.51C
[1944301081E8A62E00] [169.254.1.222] [11.480] [system] [info] Cpu Usage - LeonOS 29.07%, LeonRT: 0.27%
[2026-01-07 13:27:37.329] [depthai] [info] Environment variable DEPTHAI_RECORD is not set. Using default value: ''
[2026-01-07 13:27:37.329] [depthai] [info] Environment variable DEPTHAI_REPLAY is not set. Using default value: ''
[1944301081E8A62E00] [169.254.1.222] [1767792457.347] [host] [debug] Schema dump: {"connections":[{"node1Id":0,"node1Output":"out","node1OutputGroup":"","node2Id":1,"node2Input":"in","node2InputGroup":""}],"globalProperties":{"calibData":null,"cameraTuningBlobSize":null,"cameraTuningBlobUri":"","eepromId":0,"leonCssFrequencyHz":700000000.0,"leonMssFrequencyHz":700000000.0,"pipelineName":null,"pipelineVersion":null,"sippBufferSize":18432,"sippDmaBufferSize":16384,"xlinkChunkSize":-1},"nodes":[[1,{"alias":"","id":1,"ioInfo":[[["","in"],{"blocking":true,"group":"","id":2,"name":"in","queueSize":3,"type":3,"waitForMessage":false}]],"logLevel":1,"name":"XLinkOut","parentId":-1,"properties":[185,3,136,0,0,128,191,189,9,95,95,120,95,48,95,111,117,116,0]}],[0,{"alias":"","id":0,"ioInfo":[[["","out"],{"blocking":false,"group":"","id":1,"name":"out","queueSize":8,"type":0,"waitForMessage":false}],[["","mockIn"],{"blocking":true,"group":"","id":0,"name":"mockIn","queueSize":3,"type":3,"waitForMessage":false}]],"logLevel":1,"name":"IMU","parentId":-1,"properties":[185,4,186,2,185,5,0,0,0,129,224,1,20,185,5,0,0,0,129,144,1,21,1,10,0]}]]}
[1944301081E8A62E00] [169.254.1.222] [1767792457.348] [host] [debug] Asset map dump: {"map":{}}
[2026-01-07 13:27:37.363] [depthai] [info] Compiled without CURL support, not logging pipeline.
[1944301081E8A62E00] [169.254.1.222] [11.532] [system] [info] SIPP (Signal Image Processing Pipeline) internal buffer size '18432'B, DMA buffer size: '16384'B
IMU pipeline started. Press Ctrl+C to stop.
[1944301081E8A62E00] [169.254.1.222] [11.567] [system] [info] 
[1944301081E8A62E00] [169.254.1.222] [11.764] [IMU(0)] [info] IMU product ID:
[1944301081E8A62E00] [169.254.1.222] [11.764] [IMU(0)] [info] Part 10004563 : Version 3.9.9 Build 2
[1944301081E8A62E00] [169.254.1.222] [11.764] [IMU(0)] [info] Part 10003606 : Version 1.8.0 Build 338
[1944301081E8A62E00] [169.254.1.222] [11.764] [IMU(0)] [info] Part 10004135 : Version 5.5.3 Build 162
[1944301081E8A62E00] [169.254.1.222] [11.764] [IMU(0)] [info] Part 10004149 : Version 5.1.12 Build 183
Accelerometer timestamp: 76193838612249
Latency [ms]: 5.000000
Accelerometer [m/s^2]: x: -0.239420 y: -10.314221 z: -0.469264
Gyroscope timestamp: 76193839690249
Gyroscope [rad/s]: x: 0.011718 y: 0.009587 z: 0.018109
Accelerometer timestamp: 76193840524249
Latency [ms]: 6.000000
Accelerometer [m/s^2]: x: -0.248997 y: -10.285490 z: -0.469264
Gyroscope timestamp: 76193842146249
Gyroscope [rad/s]: x: -0.003196 y: -0.006392 z: -0.007457
Accelerometer timestamp: 76193844430249

[...]

Latency [ms]: 4.000000
Accelerometer [m/s^2]: x: -0.181959 y: -10.275913 z: -0.450110
Gyroscope timestamp: 76194513497249
Gyroscope [rad/s]: x: 0.013848 y: -0.009587 z: 0.004261
Accelerometer timestamp: 76194515552249
Latency [ms]: 5.000000
Accelerometer [m/s^2]: x: -0.248997 y: -10.323798 z: -0.517148
Gyroscope timestamp: 76194516148249
Gyroscope [rad/s]: x: 0.004261 y: 0.001065 z: -0.004261
Accelerometer timestamp: 76194517695249
Latency [ms]: 5.000000
Accelerometer [m/s^2]: x: -0.220267 y: -10.314221 z: -0.450110
Gyroscope timestamp: 76194518940249
Gyroscope [rad/s]: x: 0.007457 y: -0.003196 z: -0.003196
Accelerometer timestamp: 76194519660249
Latency [ms]: 5.000000
Accelerometer [m/s^2]: x: -0.258574 y: -10.266336 z: -0.488417
Gyroscope timestamp: 76194521272249
Gyroscope [rad/s]: x: -0.001065 y: 0.006392 z: 0.008522
Accelerometer timestamp: 76194523826249
Latency [ms]: 5.000000
Accelerometer [m/s^2]: x: -0.248997 y: -10.237606 z: -0.459687
Gyroscope timestamp: 76194523664249
Gyroscope [rad/s]: x: 0.002131 y: -0.013848 z: 0.002131
[1944301081E8A62E00] [169.254.1.222] [12.481] [system] [info] Memory Usage - DDR: 0.13 / 333.26 MiB, CMX: 2.07 / 2.50 MiB, LeonOS Heap: 27.21 / 81.17 MiB, LeonRT Heap: 2.93 / 39.20 MiB / NOC ddr: 6 MB/s
[1944301081E8A62E00] [169.254.1.222] [12.481] [system] [info] Temperatures - Average: 41.08C, CSS: 42.81C, MSS 40.51C, UPA: 40.04C, DSS: 40.97C
[1944301081E8A62E00] [169.254.1.222] [12.481] [system] [info] Cpu Usage - LeonOS 42.43%, LeonRT: 3.99%
Accelerometer timestamp: 76194525426249
Latency [ms]: 5.000000
Accelerometer [m/s^2]: x: -0.201113 y: -10.266336 z: -0.507571
Gyroscope timestamp: 76194526523249
Gyroscope [rad/s]: x: 0.001065 y: -0.008522 z: 0.013848
Accelerometer timestamp: 76194527413249
Latency [ms]: 6.000000
Accelerometer [m/s^2]: x: -0.229843 y: -10.275913 z: -0.459687
Gyroscope timestamp: 76194528632249
Gyroscope [rad/s]: x: 0.006392 y: 0.000000 z: -0.003196
Accelerometer timestamp: 76194529593249
Latency [ms]: 6.000000
Accelerometer [m/s^2]: x: -0.210690 y: -10.304645 z: -0.478840
Gyroscope timestamp: 76194531278249
Gyroscope [rad/s]: x: 0.005326 y: -0.004261 z: 0.006392
Accelerometer timestamp: 76194533714249

[...]

Latency [ms]: 4.000000
Accelerometer [m/s^2]: x: -0.229843 y: -10.285490 z: -0.478840
Gyroscope timestamp: 76194763277249
Gyroscope [rad/s]: x: 0.002131 y: -0.006392 z: -0.008522
Accelerometer timestamp: 76194765214249
Latency [ms]: 4.000000
Accelerometer [m/s^2]: x: -0.268151 y: -10.295067 z: -0.469264
Gyroscope timestamp: 76194765726249
Gyroscope [rad/s]: x: 0.001065 y: 0.004261 z: 0.009587
Accelerometer timestamp: 76194767268249
Latency [ms]: 5.000000
Accelerometer [m/s^2]: x: -0.239420 y: -10.304645 z: -0.478840
Gyroscope timestamp: 76194768194249
Gyroscope [rad/s]: x: 0.010653 y: -0.011718 z: 0.005326
Accelerometer timestamp: 76194769287249
Latency [ms]: 5.000000
Accelerometer [m/s^2]: x: -0.277727 y: -10.323798 z: -0.488417
Gyroscope timestamp: 76194770899249
Gyroscope [rad/s]: x: -0.003196 y: -0.001065 z: -0.013848
Accelerometer timestamp: 76194773016249
Latency [ms]: 3.000000
Accelerometer [m/s^2]: x: -0.258574 y: -10.256760 z: -0.450110
Gyroscope timestamp: 76194773203249
Gyroscope [rad/s]: x: -0.004261 y: 0.004261 z: 0.004261
[1944301081E8A62E00] [169.254.1.222] [13.482] [system] [info] Memory Usage - DDR: 0.13 / 333.26 MiB, CMX: 2.07 / 2.50 MiB, LeonOS Heap: 27.21 / 81.17 MiB, LeonRT Heap: 2.93 / 39.20 MiB / NOC ddr: 57 MB/s
[1944301081E8A62E00] [169.254.1.222] [13.482] [system] [info] Temperatures - Average: 41.20C, CSS: 42.58C, MSS 40.74C, UPA: 40.74C, DSS: 40.74C
[1944301081E8A62E00] [169.254.1.222] [13.482] [system] [info] Cpu Usage - LeonOS 15.54%, LeonRT: 0.05%
[1944301081E8A62E00] [169.254.1.222] [14.483] [system] [info] Memory Usage - DDR: 0.13 / 333.26 MiB, CMX: 2.07 / 2.50 MiB, LeonOS Heap: 27.21 / 81.17 MiB, LeonRT Heap: 2.93 / 39.20 MiB / NOC ddr: 13 MB/s
[1944301081E8A62E00] [169.254.1.222] [14.483] [system] [info] Temperatures - Average: 40.79C, CSS: 42.58C, MSS 40.51C, UPA: 40.04C, DSS: 40.04C
[1944301081E8A62E00] [169.254.1.222] [14.483] [system] [info] Cpu Usage - LeonOS 0.95%, LeonRT: 0.05%
[1944301081E8A62E00] [169.254.1.222] [15.484] [system] [info] Memory Usage - DDR: 0.13 / 333.26 MiB, CMX: 2.07 / 2.50 MiB, LeonOS Heap: 27.21 / 81.17 MiB, LeonRT Heap: 2.93 / 39.20 MiB / NOC ddr: 1 MB/s
[1944301081E8A62E00] [169.254.1.222] [15.484] [system] [info] Temperatures - Average: 40.51C, CSS: 42.35C, MSS 39.35C, UPA: 39.81C, DSS: 40.51C
[1944301081E8A62E00] [169.254.1.222] [15.484] [system] [info] Cpu Usage - LeonOS 0.50%, LeonRT: 0.05%
[1944301081E8A62E00] [169.254.1.222] [16.485] [system] [info] Memory Usage - DDR: 0.13 / 333.26 MiB, CMX: 2.07 / 2.50 MiB, LeonOS Heap: 27.21 / 81.17 MiB, LeonRT Heap: 2.93 / 39.20 MiB / NOC ddr: 1 MB/s
[1944301081E8A62E00] [169.254.1.222] [16.485] [system] [info] Temperatures - Average: 41.08C, CSS: 43.04C, MSS 39.58C, UPA: 40.51C, DSS: 41.20C
[1944301081E8A62E00] [169.254.1.222] [16.485] [system] [info] Cpu Usage - LeonOS 0.51%, LeonRT: 0.05%

Thanks, Finn

OskarSonc

Hey finn - two things:

The log still shows depthai 3.1.0, so the update didn’t actually apply. Can you confirm the new 3.2.1 version?
For debug logging, please use DEPTHAI_LEVEL=debug. In PowerShell:

$env:DEPTHAI_LEVEL="debug"
python depthai-core\examples\python\IMU\imu_gyroscope_accelerometer.py

Also, you can try adding this line before pipeline.start():
imu.enableFirmwareUpdate(True)

finn

Hey @OskarSonc

Updating depthai and the imu firmware seems to do the trick.

Thanks Finn

OskarSonc

Glad it did the trick 🙂