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Errors seen on vSRX and KVM when 0 Byte file is attached to Virtual USB (vUSB)



Article ID: KB36683 KB Last Updated: 08 Apr 2021Version: 1.0

Users will see error messages upon rebooting or after zeroizing a file size on a virtual USB (vUSB) mounted to KVM hosts with vSRX's installed, and the file attached to the vUSB is 0 bytes. 


When virtual USB is mounted on KVM instance running vSRX and vUSB that has a zero byte file, users might see the following via console, syslog and messages file:

(da0:umass-sim0:0:0:0): READ CAPACITY. CDB: 25 0 0 0 0 0 0 0 0 0
(da0:umass-sim0:0:0:0): CAM Status: SCSI Status Error
(da0:umass-sim0:0:0:0): SCSI Status: Check Condition
(da0:umass-sim0:0:0:0): NOT READY asc:4,3
(da0:umass-sim0:0:0:0): Logical unit not ready, manual intervention required
(da0:umass-sim0:0:0:0): Unretryable error
Opened disk da0 -> 6

KVM is unable to validate the 0-byte file on the vUSB. 


Ensure the file mounted on the vUSB is a valid file. 

Other options if it's required to have a 0 byte file on the vUSB and you want to mute the messages: 

  • ‚ÄčOn vSRX side, filter from syslog log files, and user ssh sessions by masking it with the following configuration commands:

# set system syslog user * match "!(da0)"
# set system syslog user * match "!(.*da0.*)"
# set system syslog user * match "!(.*da0:umass.*|Opened disk da0.*)
  • Masking/hiding messages on console session to vSRX when initiated on KVM side is not possible at this time. 

  • When parsing log messages, use the following command to hide:

match "!(.*kernel .*da0:umass.*|.*kernel .* Opened disk da0.*)"
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