Finding all storage devices attached to a Linux machine
If one is interested only in block storage devices, one can use lsblk from widely-available util-linux package:
$ lsblk -o KNAME,TYPE,SIZE,MODEL
KNAME TYPE SIZE MODEL
sda disk 149.1G TOSHIBA MK1637GS
sda1 part 23.3G
sda2 part 28G
sda3 part 93.6G
sda4 part 4.3G
sr0 rom 1024M CD/DVDW TS-L632M
It lends itself well to scripting with many other columns available.
You could trawl through the output of lshw and extract details about devices in the disk or tape class (and maybe others - storage class gives you details on storage controllers, scsi, sata, sas, etc).
e.g.
lshw -class disk -class tape
The -short option gives a nice compact summary. e.g. on my home zfsonlinux server/workstation/experiment-box (no tape devices unfortunately):
# lshw -class tape -class disk -class storage -short H/W path Device Class Description ========================================================= /0/100/4/0 storage JMB362 SATA Controller /0/100/5/0 scsi10 storage JMB362 SATA Controller /0/100/5/0/0.0.0 /dev/sdc disk 120GB Patriot Wildfire /0/100/b/0 scsi1 storage SAS2008 PCI-Express Fusion-MPT SAS-2 [Falcon] /0/100/b/0/0.0.0 /dev/sdd disk 1TB WDC WD10EARS-00Y /0/100/b/0/0.1.0 /dev/sde disk 1TB WDC WD10EACS-00Z /0/100/b/0/0.2.0 /dev/sdf disk 1TB WDC WD10EACS-00Z /0/100/b/0/0.3.0 /dev/sdg disk 1TB ST31000528AS /0/100/b/0/0.4.0 /dev/sdh disk 1TB ST31000528AS /0/100/b/0/0.5.0 /dev/sdi disk 1TB ST31000528AS /0/100/b/0/0.6.0 /dev/sdj disk 1TB ST31000528AS /0/100/11 scsi2 storage SB7x0/SB8x0/SB9x0 SATA Controller [AHCI mode] /0/100/11/0 /dev/sda disk 128GB Patriot Torqx 2 /0/100/11/1 /dev/sdb disk 1TB ST31000528AS /0/1 scsi11 storage /0/1/0.0.0 /dev/sdk disk 1967MB SCSI Disk /0/1/0.0.1 /dev/sdl disk SCSI Disk /0/1/0.0.2 /dev/sdm disk SCSI Disk /0/1/0.0.3 /dev/sdn disk SCSI Disk /0/2 scsi66 storage /0/2/0.0.0 /dev/sdo disk SCSI Disk /0/3 scsi67 storage /0/3/0.0.0 /dev/sdp disk 4057MB SCSI Disk
The /0/1 devices are actually a USB card-reader (there's a 2GB SD card plugged in to one of the slots), and the /0/2 device is my android phone plugged in for charging only. The 0/3 device is a 4GB USB flash drive.
lshw can produce plain text, html, xml, and json output. It can also dump hardware details into an sqlite database format.
It is packaged for debian and most other distros. The home page and source is at http://ezix.org/project/wiki/HardwareLiSter
You can use lsblk to list all block devices, along with whether or not each device is read only.
You can then use grep and awk to print the names of block devices that are not read only:
lsblk -d -n -oNAME,RO | grep '0$' | awk {'print $1'}