What filesystem(s) my Linux supports?
Answer:
E.g. To see what ext filesystems it support, use
# cat /proc/filesystems | grep ext
ext3
ext2
ext4
Apr 242010
Kill all processes accessing the a particular file/folder
Answer:
To kill all processes accessing the a particular file/folder, you can use the follow command:
# /sbin/fuser -k /data/backup
It is very useful when you want to unmount a filesystem but Linux reported the device is busy.
How to convert ext2 partition to ext3?
Answer:
Firstly, you need to create a journal on it. This can be done either the file system is mounted or unmounted.
# tune2fs -j /dev/hdaX
Then, mount the filesystem as ext3
# mount -t ext3 /dev/hdaX /mnt/somewhere
Reference: http://batleth.sapienti-sat.org/projects/FAQs/ext3-faq.html
Mar 052010
Generate dummy file in Linux
Answer:
To generate random files of fixed size (e.g. 1GB) in Linux:
dd if=/dev/zero of=test.bin bs=1000000000 count=1
You can adjust the file size by setting the bs parameter (byte size).
How to check if a file is locked in Linux?
Answer:
Suppose a file test.txt is being locked by a program, e.g. using the flock system call, how can we know if this file is really being locked?
# lsof test.txt
COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME
perl 5654 john 3uW REG 8,1 1 983057 test.txt
The W means the file is currently held by an exclusive lock. You can find more information in the link below:
