Archive for the ‘centos’ Category
Very basic SELinux troubleshooting
SELinux has been around for a while in RedHat. SELinux is Mandatory Access Control mechanism. Starting with RedHat 6, the installer automatically sets SELinux to enforcing mode. When troubleshooting something SELinux is one more thing to keep in mind. If you are fixing something and you booted with SELinux disabled, all files created since you [...]
In: centos, linux, linux tips, redhat, security
Removing file or directory via inode number
While back I was doing some work with SVM. Everything went smoothly, but after I was done I experienced some bizarre issue. I am not entirely sure how it came to be. I needed to remove a temporary mountpoint called /tmpmnt: bash-3.00# ls -l lrwxrwxrwx 1 root root 9 Nov 29 2010 bin -> ./usr/bin drwxr-xr-x 8 root sys 512 Nov 29 2010 boot drwxr-xr-x 3 root nobody 512 Nov 30 2010 cdrom drwxr-xr-x 18 root sys 4096 Jun 8 10:04 dev drwxr-xr-x 2 root sys 512 Jun 8 2011 devices drwxr-xr-x 88 root sys 4608 Jun 8 10:04 etc drwxr-xr-x 3 root sys 512 Nov 30 2010 export dr-xr-xr-x 1 root root 1 Jun 8 10:04 home drwxr-xr-x 18 root sys 512 Nov 29 2010 kernel drwxr-xr-x 8 root bin 5632 Nov 29 2010 lib drwx—— 2 root root 8192 Nov 29 2010 lost+found [...]
In: centos, linux, linux tips, redhat, solaris, solaris tips
Identifying a failed disk using dd
A while back I had the “fortune” of having to deal with replacement of a failed disk inside a disk array of some HP-UX machine. Never mind lack of any information regarding the hardware setup (dual controllers, multipathing, etc.)… The biggest problem was identifying the failed disk. Oh, and throw some LVM into that… Of [...]
In: centos, hpux, linux, linux tips, linux utilities, redhat, solaris, solaris tips, solaris utilities
Unmounting stale NFS mount points in Linux
Unmounting stale NFS mount points in Linux can be royal pain sometimes. In Solaris, umount -f does the job just fine. Linux on the other hand seems to get stuck if you use only -f switch. It just hangs there until you reboot the system. If you use lazy umount, that will probably help you [...]
In: centos, linux, linux tips, linux utilities, redhat
Why it’s not a good idea to remove active log file
So, someone deleted a log file of a running process because partition was running out of space. That’s seemingly logical thing to do, but not a wise one. What ended up happening was that the filesystem was still getting filled and deleting the log file made no difference whatsoever. So what happened? When the log [...]
In: centos, linux, linux tips, linux utilities, redhat
