In this article we are going to learn how to configure loop device. But first we will checkout what loop device really is .
Loop device is basically a file which we convert into partition . Like we make raid on hard disk partition, sometimes we don’t have that much hard disk space and we want file to act as an entire file system so thus where loop device is used .
Now to configure follow these steps:
- First we create a file
root@dhcppc2 ~]# touch a .txt
- Now we give this file a size .
[root@dhcppc2 ~]# dd if=/dev/zero of=a.txt bs=1M count=1000 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 17.1456 seconds, 61.2 MB/s
- After giving this file size we have to convert this file into partition (loop device)
[root@dhcppc2 ~]# losetup /dev/loop0 a.txt
- To check whether its been created or not you can type
[root@dhcppc2 ~]# losetup -a /dev/loop0: :618408 (a.txt)
- Now we will mount this loop device but before mounting create a folder where you want to mount and format it before mounting. Then mount
[root@dhcppc2 ~]# mkdir B [root@dhcppc2 ~]# mkfs.ext3 /dev/loop0 mke2fs 1.39 (29-May-2006) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) 128000 inodes, 256000 blocks 12800 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=264241152 8 block groups 32768 blocks per group, 32768 fragments per group 16000 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376 Writing inode tables: done Creating journal (4096 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 20 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. [root@dhcppc2 ~]# mount /dev/loop0 B
- for checking whether its been mounted or not type
[root@dhcppc2 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/sda1 15G 3.5G 10G 26% / tmpfs 506M 0 506M 0% /dev/shm /dev/loop0 985M 18M 918M 2% /root/B
SO THIS HOW YOU CAN CREATE LOOP DEVICE