grub HowTo - Linux / Unix Q & A from nixCraft

JBD: Barrier-based Sync Failed On md0-8 – Disabling Barriers Error and Solution

last updated September 4, 2011 in Linux

I‘ve used the mdadm command line utility to setup and manage software RAID 6 under Debian Linux server. However, I get the following message in /var/log/messages file:
[ 14.003707] JBD: barrier-based sync failed on md0-8 – disabling barriers

How do I fix the message ‘JBD error message “barrier-based sync failed”‘?

Debian Linux: Set a Serial Console

last updated January 22, 2011 in Debian / Ubuntu

How do I set up a serial console on Debian Linux HP server for troubleshooting and login purpose?

Turn on SELinux in Redhat or CentOS Linux Over Remote SSH Session

last updated February 15, 2010 in CentOS

My hosting company disabled SELinux protection. How do I turn on SELinux over remote ssh session without distributing existing networking services?

Linux Disable USB Devices (Disable loading of USB Storage Driver)

last updated September 21, 2016 in CentOS, Debian / Ubuntu, Fedora Linux, Hardware, Linux, RedHat and Friends, Security, Storage, Suse, Troubleshooting

In our research lab I’d like to disable all USB devices connected to our HP Red Hat Linux based workstations. I’d like to disable USB flash or hard drives, which users can use with physical access to a system to quickly copy sensitive data from it. How do I disable USB device support under RHEL 5.x workstation operating systems?

Linux: Skip or Bypass a Fsck

last updated December 20, 2008 in CentOS, Debian / Ubuntu, Fedora Linux, Linux, OpenBSD, Suse, Troubleshooting, Ubuntu Linux, UNIX

Q. I know how to force fsck on the next reboot using /forcefsck file. But how do I skip or bypass a fsck on reboot? How to stop a FSCK from prompting or running automatically when rebooting server.

Linux CDROM: Lost Interrupt / status=0x59 (0x40) DriverReady SeekComplete DataRequest Error and Solution

last updated October 29, 2008 in Hardware, Linux, Troubleshooting

Q. My CDROM drive attached to Stratus ftServer 6210 is not working and it is dumping me with following error:

hdb: lost interrupt
hdb: lost interrupt
hdb: lost interrupt
hdb: status error: status=0x59 { DriverReady SeekComplete DataRequest
Error }
hdb: status error: status=0x40 { LastFailedSense=0x04 }
ide: failed opcode was: unknown
hdb: drive not ready for command
hdb: lost interrupt
hdb: status error: status=0x59 { DriverReady SeekComplete DataRequest
Error }
hdb: status error: status=0x40 { LastFailedSense=0x04 }

How do I fix this error under Linux?

How To Check and Use Serial Ports Under Linux

last updated January 28, 2010 in CentOS, Debian / Ubuntu, Hardware, Linux, Networking, Suse, Troubleshooting, Ubuntu Linux

How do I check and configure serial ports under Linux for various purposes such as modem, connecting null modems or connect a dumb terminal?
Continue reading “How To Check and Use Serial Ports Under Linux”