Hi. I have a Supermicro 5018D-FN4T (Xeon D-1541 based SBC) that I use for virtualization. I’m running Centos 7.3 on it (updated), with the CentOS-QEMU-EV.repo repository as the source for virtualization packages. I run an Ubuntu 16.04-2 guest VM on it, which is ordinary enough. What’s perhaps less ordinary is that I’ve attached a Lexar Media, Inc. “Lexar Professional Workflow CR1 CFast 2.0 USB 3.0 Reader” (LRWCR1TBNA) as well as a WEme Superspeed Aluminum USB 3.0 Multi-in-1 Card Reader … for CF/SD/TF Micro SD. Here’s the relevant lsusb output: Bus 004 Device 004: ID 0bda:0309 Realtek Semiconductor Corp. Bus 004 Device 025: ID 05dc:ba04 Lexar Media, Inc. and both are hanging off of an Amazon Basics 4-port USB 3.0 hub: Bus 004 Device 002: ID 2109:8110 VIA Labs, Inc. Hub The Ubuntu VM I use for doing buildroot cross builds of an embedded Linux environment, which I then burn the image of onto a CFast card, having attached the Lexar card reader to the guest VM. Problem is that the card reader is extremely dodgy, and sometimes I guess a flurry of messages on the virtualization host complaining about the device: Mar 11 15:52:46 kvm1 kernel: usb 4-2.2: Disable of device-initiated U1 failed. Mar 11 15:52:46 kvm1 kernel: usb 4-2.2: Disable of device-initiated U2 failed. Mar 11 15:52:46 kvm1 kernel: usb 4-2.2: Set SEL for device-initiated U1 failed. Mar 11 15:52:46 kvm1 kernel: usb 4-2.2: Set SEL for device-initiated U2 failed. Mar 11 15:52:47 kvm1 kernel: usb 4-2.2: reset SuperSpeed USB device number 25 using xhci_hcd Mar 11 15:52:47 kvm1 kernel: scsi host13: uas Mar 11 15:52:47 kvm1 kernel: scsi 13:0:0:0: Direct-Access Lexar WorkflowCR1 0 PQ: 0 ANSI: 6 Mar 11 15:52:47 kvm1 kernel: sd 13:0:0:0: [sda] 30198988 512-byte logical blocks: (15.4 GB/14.3 GiB) Mar 11 15:52:47 kvm1 kernel: sd 13:0:0:0: Attached scsi generic sg0 type 0 Mar 11 15:52:47 kvm1 kernel: sd 13:0:0:0: [sda] Write Protect is off Mar 11 15:52:47 kvm1 kernel: sd 13:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA Mar 11 15:52:47 kvm1 kernel: sda: sda1 sda2 Mar 11 15:52:47 kvm1 kernel: sd 13:0:0:0: [sda] Attached SCSI removable disk Mar 11 15:52:48 kvm1 kernel: usb 4-2.2: usbfs: process 4354 (CPU 3/KVM) did not claim interface 0 before use Mar 11 15:52:48 kvm1 kernel: usb 4-2.2: usbfs: process 4354 (CPU 3/KVM) did not claim interface 0 before use Mar 11 15:53:21 kvm1 kernel: usb 4-2.2: usbfs: process 4355 (CPU 4/KVM) did not claim interface 0 before use Mar 11 15:53:21 kvm1 kernel: usb 4-2.2: reset SuperSpeed USB device number 25 using xhci_hcd Mar 11 15:53:21 kvm1 kernel: usb 4-2.2: reset SuperSpeed USB device number 25 using xhci_hcd but lately it just kills my VM when I’m writing to the device. So from annoying to a serious potential for losing work. I run “yum update” a couple of times a week but now I’m thinking that was a mistake, since this has gone from being ultra-reliable to being a hazard. Is there a workaround? Would I be better off plugging the USB 3.0 card-reader into a USB 2.0 hub and settling for slower throughput… but not crashing? Below, for instance, I was doing a “dd if=xyzzy of=/dev/sda bs=1M” where /dev/sda is the device assigned to the USB card storage device. Thanks, -Philip URL for ABRT report: https://da.gd/emJO