Q. I am new to Linux and I not able to understand /dev/hdc (is it C: drive?) under Linux. This is quite confusing for a new Linux user like me. What device naming convention followed by Linux? Can you explain it in layman’s term?
A. Linux does not follows DOS or Windows XP style partition names or drive names. It is true that it is a bit confusing for a new Linux user. Linux use combination of bus and . For example if you are using IDE hard disk or CDROM it is will use HD word. If you are using SCSI interface it will use SD word.
A typical home pc or laptop has 2 or 4 IDE channels as follows:
- ide0 = primary
- ide1 = secondary
- ide2 = tertiary
- ide3 = quaternary
- ide0 = primary master = hda
- ide1 = primary slave = hdb
- ide2 = secondary master = hdc
- ide3 = secondary slave = hdd
and so on…
SCSI devices are listed as devices sda, sdb, sdc, sdd, sde, sdf, and sdg in the /dev directory. Similarly, partitions on these disks can range from 1 to 16 and are also in the /dev directory.
Now each hard drive has 4 primary partitions (limit of PC x86 architecture). First partition is denoted by number 1. For example:
- First partition : /dev/hda1
- Second partition : /dev/hda2
- Third partition : /dev/hda3
- Fourth partition : /dev/hda4
You can run command fdisk -l to display list of partitions:
# fdisk -l
Disk /dev/hda: 20.0 GB, 20060651520 bytes 255 heads, 63 sectors/track, 2438 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/hda1 * 1 1275 10241406 83 W95 FAT32 /dev/hda2 1276 1530 2048287+ 82 Linux swap / Solaris Disk /dev/hdb: 80.0 GB, 80060424192 bytes 255 heads, 63 sectors/track, 9733 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/hdb1 * 1 2432 19535008+ 83 Linux /dev/hdb2 2433 2554 979965 82 Linux swap / Solaris /dev/hdb3 2555 6202 29302560 83 Linux /dev/hdb4 6203 9733 28362757+ 5 Extended /dev/hdb5 6203 9733 28362726 83 Linux
In above output /dev/hda1 is FAT32 partition with Windows XP installed (windows XP/Vista C: ).