Finding the target "/dev/sg" device

General description

This section describes how to find proper "/dev/sg" device for CHARON mapping

Procedures of finding the target "/dev/sg" device

Method 1

Open a terminal console and issue:

# lsscsi -g

If the "lsscsi" command is not installed on your system, use "yum install lsscsi" to make it available. If you cannot install "lsscsi", use method 2 or method 3 described below.

Output example1:

[0:0:0:0] disk VMware Virtual disk 1.0 /dev/sda /dev/sg0

[0:0:10:0] tape COMPAQ SDLT320 5F5F /dev/st0 /dev/sg9

[0:0:11:0] tape COMPAQ SDLT320 5F5F /dev/st1 /dev/sg10

[0:0:12:0] mediumx COMPAQ MSL5000 Series 0520 /dev/sch0 /dev/sg11

Output example2:

[0:0:0:0] disk VMware, VMware Virtual S 1.0 /dev/sda /dev/sg0

[4:0:0:0] cd/dvd NECVMWar VMware SATA CD01 1.00 /dev/sr0 /dev/sg1

Method 2

Open a terminal console and issue:

# cat /proc/scsi/sg/device_hdr; cat /proc/scsi/sg/devices

Output example:

host    chan    id      lun     type    opens qdepth bus    online
4       0 0       0       5       1       1       0      1
5       0       0       0       0       1       1       0      1

The fifth column ("type") value has the following correspondence:

Value	Device

Value	Device
0	Disk
1	Tape
5	CD-ROM
8	Tape changer

The "N" in the "/dev/sgN" device is the line number (starting from 0) corresponding to the output provided by the commands above without taking the header into account so here "/dev/sg0" corresponds to the the CD-ROM.

Method 3

On a freshly booted system, issue the following command:

# dmesg | grep sg

The output will look like that:

[ 1.503622] sr 4:0:0:0: Attached scsi generic sg0 type 5
[ 1.780897] sd 5:0:0:0: Attached scsi generic sg1 type 0

This table lists all the devices, not only the real SCSI ones (SATA/IDE for example). CHARON supports only real SCSI devices.