Unix - Disk Management

Identifying the harddisks installed

• Listing all the disks and drives attached to the system
  
  

  # camcontrol devlist    (or, atacontrol list)
  
  at scbus2 target 0 lun 0 (ada0,pass0)
  at scbus3 target 0 lun 0 (cd0,pass1)



• Listing harddisks detected during the system bootup
  
  

  # dmesg | grep ad 
  
  ada0 at ata4 bus 0 scbus2 target 0 lun 0
  ada0:  ATA-8 SATA 2.x device
  ada0: 300.000MB/s transfers (SATA 2.x, UDMA5, PIO 8192bytes)
  ada0: 238418MB (488281250 512 byte sectors: 16H 63S/T 16383C)
  ada0: Previously was known as ad4
  Trying to mount root from ufs:/dev/ada0p2 [rw]...



• Listing harddisks and their partitions
  
  

  # ls /dev | grep ad
  
  ad4
  ad4p1
  ad4p2
  ad4p3
  ada0
  ada0p1
  ada0p2
  ada0p3



• Listing hardware level information of a harddisks
  
  

  # diskinfo -c ada0
  ada0
     512             # sectorsize
     250000000000    # mediasize in bytes (232G)
     488281250       # mediasize in sectors
     0               # stripesize
     0               # stripeoffset
     484406          # Cylinders according to firmware.
     16              # Heads according to firmware.
     63              # Sectors according to firmware.
     WD-WMAV12345678 # Disk ident.
  
  I/O command overhead:
     time to read 10MB block      0.124816 sec = 0.006 msec/sector
     time to read 20480 sectors   2.126440 sec = 0.104 msec/sector
     calculated command overhead               = 0.098 msec/sector
  



• #fdisk ada0
  
  

  ******* Working on device /dev/ada0 *******
  parameters extracted from in-core disklabel are:
  cylinders=484521 heads=16 sectors/track=63 (1008 blks/cyl)
  
  Figures below won't work with BIOS for partitions not in cyl 1
  parameters to be used for BIOS calculations are:
  cylinders=484521 heads=16 sectors/track=63 (1008 blks/cyl)
  
  Media sector size is 512
  Warning: BIOS sector numbering starts with sector 1
  Information from DOS bootblock is:
  The data for partition 1 is:
  sysid 238 (0xee),(EFI GPT)
      start 1, size 488397167 (238475 Meg), flag 80 (active)
   beg: cyl 0/ head 1/ sector 1;
   end: cyl 1023/ head 255/ sector 63
  

Identifying the harddisk partitions

• Identifying basic information about harddisk partitions
  
  

  # gpart show
  
  =>       34  488281183  ada0  GPT  (232G)
           34        128     1  freebsd-boot  (64k)
          162  478150528     2  freebsd-ufs  (228G)
    478150690    8388608     3  freebsd-swap  (4.0G)
    486539298    1741919        - free -  (850M)
  



• Displaying detailed information of harddisk partitions
  
  

  # gpart list
  
  Geom name: ada0
  modified: false
  state: OK
  fwheads: 16
  fwsectors: 63
  last: 488281216
  first: 34
  entries: 128
  scheme: GPT
  Providers:
  1. Name: ada0p1
     Mediasize: 65536 (64k)
     Sectorsize: 512
     Stripesize: 0
     Stripeoffset: 17408
     Mode: r0w0e0
     rawuuid: 740aff84-9a1e-11e3-b778-002219173177
     rawtype: 83bd6b9d-7f41-11dc-be0b-001560b84f0f
     label: (null)
     length: 65536
     offset: 17408
     type: freebsd-boot
     index: 1
     end: 161
     start: 34
  2. Name: ada0p2
     Mediasize: 244813070336 (228G)
     Sectorsize: 512
     Stripesize: 0
     Stripeoffset: 82944
     Mode: r1w1e1
     rawuuid: 740b80b0-9a1e-11e3-b778-002219173177
     rawtype: 516e7cb6-6ecf-11d6-8ff8-00022d09712b
     label: (null)
     length: 244813070336
     offset: 82944
     type: freebsd-ufs
     index: 2
     end: 478150689
     start: 162
  3. Name: ada0p3
     Mediasize: 4294967296 (4.0G)
     Sectorsize: 512
     Stripesize: 0
     Stripeoffset: 17408
     Mode: r1w1e0
     rawuuid: 740eaebd-9a1e-11e3-b778-002219173177
     rawtype: 516e7cb5-6ecf-11d6-8ff8-00022d09712b
     label: (null)
     length: 4294967296
     offset: 244813153280
     type: freebsd-swap
     index: 3
     end: 486539297
     start: 478150690
  Consumers:
  1. Name: ada0
     Mediasize: 250000000000 (232G)
     Sectorsize: 512
     Mode: r2w2e3
  




• df -h
  
  Filesystem      Size    Used   Avail Capacity  Mounted on
  /dev/ada0p2     220G    7.6G    195G     4%    /
  devfs           1.0k    1.0k      0B   100%    /dev
  nfsServer:/home 435G     15G    420G     3%    /usr/home
  

Mounting and unmounting external drives

For a USB memory stick,

• # mount -t msdosfs /dev/da0s1 /tmp/usb
• # umount /tmp/usb

While inserting a USB memory stick, a notification on the console will indicate the new device location like /dev/da0. But, you have to find the active partition of the drive like /dev/da0s1 to mount (# ls /dev | grep da could be used).


Note: Unix commands and file locations used here have been tested on FreeBSD systems.