Disk in Linux machine are internal or external

Linux and Unix-Like Red Hat
1

How to check whether the disk in linux machine are internal or external ( from nas or san). How to identify internal(local) and external disks. Following are some details of my server. Thanks.

#df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda3              15G  3.5G   10G  26% /
/dev/sda5             103G   90G  7.7G  93% /ad01
/dev/sda1              99M   13M   82M  13% /boot
tmpfs                 7.9G     0  7.9G   0% /dev/shm

#lsusb
Bus 002 Device 001: ID 0000:0000
Bus 002 Device 004: ID 04b4:6560 Cypress Semiconductor Corp. CY7C65640 USB-2.0 "TetraHub"
Bus 002 Device 003: ID 04b4:6560 Cypress Semiconductor Corp. CY7C65640 USB-2.0 "TetraHub"
Bus 002 Device 002: ID 04b4:6560 Cypress Semiconductor Corp. CY7C65640 USB-2.0 "TetraHub"
Bus 002 Device 005: ID 0928:0007 Oxford Semiconductor, Ltd
Bus 005 Device 001: ID 0000:0000
Bus 003 Device 001: ID 0000:0000
Bus 003 Device 002: ID 04b3:4010 IBM Corp.
Bus 006 Device 001: ID 0000:0000
Bus 004 Device 001: ID 0000:0000
Bus 001 Device 001: ID 0000:0000
#  ls -ltr
total 0
lrwxrwxrwx 1 root root 10 Oct  7 21:51 usb-HL-DT-ST_DVDRAM_GSA-T50N_M2I98H90832 -> ../../scd0
lrwxrwxrwx 1 root root  9 Oct  7 21:51 scsi-3600508e000000000ff85ab918d3ce200 -> ../../sda
lrwxrwxrwx 1 root root 10 Oct  7 21:51 scsi-3600508e000000000ff85ab918d3ce200-part4 -> ../../sda4
lrwxrwxrwx 1 root root 10 Oct  7 21:51 scsi-3600508e000000000ff85ab918d3ce200-part2 -> ../../sda2
lrwxrwxrwx 1 root root 10 Oct  7 21:51 scsi-3600508e000000000ff85ab918d3ce200-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 Oct  7 21:51 scsi-3600508e000000000ff85ab918d3ce200-part3 -> ../../sda3
lrwxrwxrwx 1 root root 10 Oct  7 21:51 scsi-3600508e000000000ff85ab918d3ce200-part5 -> ../../sda5
2

To see already mounted NAS/SAN:

mount|grep //

Hope this helps

3

Thanks for replying, "mount|grep //" is not showing any output. I tried it on a machine which I am sure contained the disk from nas,