1. IDE Hard disk names starts with ad – /dev/ad0 first IDE hard disk, /dev/ad1 second hard disk and so on
2. SATA/SSD (ATA Direct Access device driver) disk names starts with ad – /dev/ada, /dev/sdb and so on.
3. SCSI Hard disk names starts with da – /dev/da*
4. IDE CDROM/RW/DVD names starts with acd – /dev/acd*
5. SCSI CDROM/RW/DVD names starts with cd – /dev/cd*

List all detected hard disk / cdroms / SSDs in FreeBSD

Type the following grep command, enter:
# egrep 'da[0-9]|cd[0-9]' /var/run/dmesg.boot
OR
# egrep 'ad[0-9]|cd[0-9]' /var/run/dmesg.boot
Sample outputs:

acd0: DVDROM  at ata0-slave UDMA33
ad4: 239372MB  at ata2-master SATA150
ad6: 239372MB  at ata3-master SATA150
Trying to mount root from ufs:/dev/ad4s1a

From above output it is clear that I’ve the following storage installed on my FreeBSD server:

1. ad4 : My First hard disk connected to ATA channel 2
2. ad6: My Second hard disk connected to ATA channel 3
3. acd0 : My DVD ROM

geom utility

Try to show detailed information about disks using geom:
# geom disk list
# geom disk list ada5
# geom disk list ada2
Sample outputs:

Geom name: ada2
Providers:
1. Name: ada2
   Mediasize: 64023257088 (60G)
   Sectorsize: 512
   Stripesize: 4096
   Stripeoffset: 0
   Mode: r0w0e0
   descr: SanDisk SD6SB1M064G1022I
   lunid: 5001b44e71f4a5a6
   ident: 152041400742
   rotationrate: 0
   fwsectors: 63
   fwheads: 16

You can filter out info using the egrep command/grep command:
# geom disk list ada3 | grep Mediasize
Sample outputs

Mediasize: 6001175126016 (5.5T)

atacontrol command (for older version of FreeBSD)

The atacontrol utility is a control program that provides the user access and control to the FreeBSD ata (IDE / SATA hard disk) subsystem.

WARNING! These examples may crash your computer and loss of data if executed improperly. Please exercise caution when using atacontrol command!

The list option can list all hard disk, enter:
# atacontrol list
Output:

ATA channel 0:
    Master:      no device present
    Slave:  acd0  ATA/ATAPI revision 7
ATA channel 1:
    Master:      no device present
    Slave:       no device present
ATA channel 2:
    Master:  ad4  Serial ATA II
    Slave:       no device present
ATA channel 3:
    Master:  ad6  Serial ATA II
    Slave:       no device present

Say hello to camcontrol command

The CAM subsystem provides a uniform and modular system for the implementation of drivers to control various SCSI and ATA devices, and to utilize different SCSI and ATA host adapters through host adapter drivers. Use the camcontrol utility to access the CAM subsystem.

List all physical devices

Type the following command:
# camcontrol devlist
Sample outputs:

How do I list current partition information?

Use the following command:
# gpart show
Sample outputs:

=>      34  31277165  ada3  GPT  (14G)
        34      1024     1  bios-boot  (512k)
      1058         6        - free -  (3.0k)
      1064  31275184     2  freebsd-zfs  (14G)
  31276248       951        - free -  (475k)
 
=>         34  11721045101  ada0  GPT  (5.5T)
           34           94        - free -  (47k)
          128      4194304     1  freebsd-swap  (2.0G)
      4194432  11716850696     2  freebsd-zfs  (5.5T)
  11721045128            7        - free -  (3.5k)
 
=>         34  11721045101  ada1  GPT  (5.5T)
           34           94        - free -  (47k)
          128      4194304     1  freebsd-swap  (2.0G)
      4194432  11716850696     2  freebsd-zfs  (5.5T)
  11721045128            7        - free -  (3.5k)
 
=>         34  11721045101  ada5  GPT  (5.5T)
           34           94        - free -  (47k)
          128      4194304     1  freebsd-swap  (2.0G)
      4194432  11716850696     2  freebsd-zfs  (5.5T)
  11721045128            7        - free -  (3.5k)
 
=>         34  11721045101  ada6  GPT  (5.5T)
           34           94        - free -  (47k)
          128      4194304     1  freebsd-swap  (2.0G)
      4194432  11716850696     2  freebsd-zfs  (5.5T)
  11721045128            7        - free -  (3.5k)
 
=>       34  234441581  ada4  GPT  (111G)
         34         94        - free -  (47k)
        128  234441480     1  freebsd-zfs  (111G)
  234441608          7        - free -  (3.5k)
 
=>       34  125045357  ada2  GPT  (59G)
         34         94        - free -  (47k)
        128  125045256     1  freebsd-zfs  (59G)
  125045384          7        - free -  (3.5k)

Using GEOM to probes disks

Type the following command (source):

## this run script using sh ##
 
sh -c '. /usr/share/bsdconfig/device.subr;f_device_menu "" "" "" DISK'

Sample outputs:

A shell script to list and detect FreeBSD server disks

Create a shell script named showdisk as follows:

#!/bin/sh
# Name: showdisk
# Author: FrauBSD
#-----------------------------------------
. /usr/share/bsdconfig/device.subr || exit
[ "$( id -u )" -eq 0 ] && WITH_CAMCONTROL=1
while :; do
	info="gpart(8) show %s:\n%s\n\n" disk= gpart= inquiry= identify=
        device=$( msg_cancel=Done f_device_menu "$DIALOG_TITLE" \
		"Select a disk device" "$hline_arrows_tab_enter" \
                $DEVICE_TYPE_DISK 2>&1 ) || break
        $device get name disk
	gpart=$( gpart show $disk 2>&1 )
	if [ "$WITH_CAMCONTROL" ]; then
		inquiry=$( camcontrol inquiry $disk 2>&1 )
		identify=$( camcontrol identify $disk 2>&1 )
	else
		info="${info}WARNING! Must be root to use camcontrol(8)!\n"
	fi
	[ "$inquiry" ] && info="${info}camcontrol(8) inquiry $disk:\n%s\n\n"
	[ "$identify" ] && info="${info}camcontrol(8) identify $disk:\n%s\n"
	f_show_msg "$info" "$disk" "$gpart" \
		${inquiry:+"$inquiry"} ${identify:+"$identify"}
done

Next, execute the shell script in FreeBSD:
chmod +x showdisk
./showdisk

FreeBSD print the attached disk size

Run diskinfo command:
diskinfo -v disk_name
diskinfo -v ada4
diskinfo -v ada1
Sample outputs:

ada1
	512         	# sectorsize
	6001175126016	# mediasize in bytes (5.5T)
	11721045168 	# mediasize in sectors
	4096        	# stripesize
	0           	# stripeoffset
	11628021    	# Cylinders according to firmware.
	16          	# Heads according to firmware.
	63          	# Sectors according to firmware.
	HGST HDN726060ALE614	# Disk descr.
	K1JVDUGD    	# Disk ident.
	No          	# TRIM/UNMAP support
	7200        	# Rotation rate in RPM
	Not_Zoned   	# Zone Mode

So my disk size is 6TB. Another outputs from SanDisk SSD installed on FreeBSD 12.x server:

lsblk command

Let us install the lsblk command as follows:
sudo pkg install lsblk
Sample outputs:

Updating FreeBSD repository catalogue...
FreeBSD repository is up to date.
All repositories are up to date.
The following 1 package(s) will be affected (of 0 checked):

New packages to be INSTALLED:
	lsblk: 1.0

Number of packages to be installed: 1

5 KiB to be downloaded.

Proceed with this action? [y/N]: y
[1/1] Fetching lsblk-1.0.txz: 100%    5 KiB   4.9kB/s    00:01    
Checking integrity... done (0 conflicting)
[1/1] Installing lsblk-1.0...
[1/1] Extracting lsblk-1.0: 100%

Run it as follows:
lsblk
## get a list of actual disks ##
sysctl kern.disks
## find info about the ada0 disk ##
lsblk da0

Conclusion

You learned how to find information about the installed hard drive and disk size in FreeBSD using command line options. See camcontrol man page here and gpart man page too.