This article explains the reason for 'kernel: umass1: BBB bulk-in/bulk-out clear stall failed, TIMEOUT' message and the steps to overcome it.

Log Messages:

Nov 17 18:32:27 /kernel: %KERN-2: umass0: BBB bulk-out clear stall failed, TIMEOUT"
Nov 17 18:44:23 /kernel: %KERN-2: umass0: BBB bulk-in clear stall failed, TIMEOUT"
Nov 17 18:35:42 /kernel: %KERN-2: umass0: BBB bulk-in clear stall failed, TIMEOUT"
Nov 17 18:36:47 /kernel: %KERN-2: umass0: BBB bulk-out clear stall failed, TIMEOUT"
Nov 17 18:40:03 /kernel: %KERN-2: umass0: BBB bulk-in clear stall failed, TIMEOUT"
Nov 17 18:38:57 /kernel: %KERN-2: umass0: BBB reset failed, TIMEOUT"

Sometimes, the symptoms below may also be seen:

1. SSH/Telnet freezes the device
2. Cannot commit or collect RSI from device

One or more of the following reasons:

1. An issue with hard disk/NAND flash
2. Corrupt routing engine file system
3. Hardware fault on routing engine

The error messages displayed in the symptoms target an error with the file system's normal functions. Thus, could be a possible corruption of disks on RE.

If you have access to the device, follow the steps below as a last resort to recover the device.

1. Re-image the problematic switch using KB20643 - Rewrote entire filesystem [juniper.net] .

2. Check the flash through 'NAND Media Check' utility.

> start shell user root
[Enter root password]
% nand-mediack -C
Media check on da0 on ex platforms     

WARNING:   This procedure will format the switch and all configurations will be lost.  

If the format install does not resolve this issue, it is a possible hardware issue that will leave the device unrecoverable.

Restart the RE in a Maintenance Window to overcome the issue and see if the error stops appearing after the restart. A restart will re-initiate all features and functionalities and prevent any transient error from re-surfacing. If the issue still persists, contact JTAC for further assistance.