Disks

Review the information below regarding disks.

SCSI Disks

SCSI disk names depend on the particular controller used and the SCSI ID of the disk. For most controllers, the name is ordered according to either ascending SCSI ID or descending SCSI ID.

The name of a SCSI disk is /dev/sd x

where x can be a, b, c, d, e, f, g, …

/dev/sda would be the first SCSI disk, /dev/sdb would be the second SCSI disk, and so on.

SCSI disks share the same naming structure for partitions as all other disks.

(E)IDE

(E)IDE disk names depend on their location and configuration (Master or Slave) on the (E)IDE bus. Unlike SCSI devices, (E)IDE disk names are shared with (E)IDE CD-ROM devices.

/dev/hda	The master on the first IDE bus.
/dev/hdb	The slave on the first IDE bus.
/dev/hdc	The master on the second IDE bus.
/dev/hdd	The slave on the second IDE bus.

Partition Names

The partition naming scheme is the name of the disk, with a suffix designating the partition. The first 4 partitions are the primary or extended partitions and any partition number greater than 5 is an extended partition. So, /dev/hda1 would be the first partition on the master hard drive on the first IDE bus.

Floppy Disks

Writing to a Floppy Disk

The UNIX designation of the floppy disk in Linux is /dev/fd0H1440. This is a 1.44 MB floppy disk drive.

Device is write-protected

When Linux is installed, the permissions are set to 660 for the 3.5 inch 1.44 floppy device /dev/fd0H1440 and for the tape device /dev/nst0. Because the user pick is not a root user, the permissions are not sufficient for D3. As a result, when a D3 process attempts to write to the floppy, a message displays indicating that the drive is write-protected. To write to the device from D3 execute the command:

If using floppy:

chmod 666 /dev/fd0H1440

If using tape:

chmod 666 /dev/nst0

WARNING

When writing to a floppy disk (for example, if you are performing an account-save or a t-dump), you must execute either the t-det (detach the tape) or t-rew (rewind the tape) command and wait for the device light to turn off before removing the floppy disk from the device. The floppy device may not clear the last buffer if one of the two commands is not executed. Consequently, some of the data may not be written to the floppy disk.