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7 linux fdisk command examples to manage hard disk partition

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7 linux fdisk command examples to manage hard disk partition

  1. 1. 7  Linux  fdisk  Command  Examples  to  Manage  Hard  Disk  ParFFon hPp://www.thegeekstuff.com/2010/09/linux-­‐fdisk/ Home About Free  eBook Archives Best  of  the  Blog Contact 7  Linux  fdisk  Command  Examples  to  Manage  Hard  Disk  Par;;on by  Balakrishnan  Mariyappan  on  September  14,  2010 1 Like 4 Tweet 10 On  Linux  distribuFons,  fdisk  is  the  best  tool  to  manage  disk  parFFons.  fdisk  is  a text  based  uFlity. Using  fdisk  you  can  create  a  new  parFFon,  delete  an  exisFng  parFFon,  or  change  exisFng  parFFon. Using  fidsk  you  are  allowed  to  create  a  maximum  of  four  primary  parFFon,  and  any  number  of  logical  parFFons,  based  on  the  size  of  the disk.1  of  11 18  Apr  12  7:29  pm
  2. 2. 7  Linux  fdisk  Command  Examples  to  Manage  Hard  Disk  ParFFon hPp://www.thegeekstuff.com/2010/09/linux-­‐fdisk/ Keep  in  mind  that  any  single  parFFon  requires  a  minimum  size  of  40MB. In  this  arFcle,  let  us  review  how  to  use  fdisk  command  using  pracFcal  examples. Warning:  Don’t  delete,  modify,  or  add  parFFon,  if  you  don’t  know  what  you  are  doing.  You  will  lose  your  data! 1.  View  All  Exis;ng  Disk  Par;;ons  Using  fdisk  -­‐l Before  you  create  a  new  parFFon,  or  modify  an  exisFng  parFFon,  you  might  want  to  view  all  available  parFFon  in  the  system. Use  fdisk  -­‐l  to  view  all  available  parFFons  as  shown  below. # fdisk -l Disk /dev/sda: 80.0 GB, 80026361856 bytes 255 heads, 63 sectors/track, 9729 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0xf6edf6ed Device Boot Start End Blocks Id System /dev/sda1 1 1959 15735636 c W95 FAT32 (LBA) /dev/sda2 1960 5283 26700030 f W95 Extd (LBA) /dev/sda3 5284 6528 10000462+ 7 HPFS/NTFS /dev/sda4 6529 9729 25712032+ c W95 FAT32 (LBA) /dev/sda5 * 1960 2661 5638752 83 Linux /dev/sda6 2662 2904 1951866 83 Linux /dev/sda7 2905 3147 1951866 83 Linux /dev/sda8 3148 3264 939771 82 Linux swap / Solaris /dev/sda9 3265 5283 16217586 b W95 FAT32 The  above  will  list  parFFons  from  all  the  connected  hard  disks.  When  you  have  more  than  one  disk  on  the  system,  the  parFFons  list  are ordered  by  the  device’s  /dev  name.  For  example,  /dev/sda,  /dev/sdb,  /dev/sdc  and  so  on. 2.  View  Par;;ons  of  a  Specific  Hard  Disk  using  fdisk  -­‐l  /dev/sd{a} To  view  all  parFFons  of  the  /dev/sda  hard  disk,  do  the  following. # fdisk -l /dev/sda View  all  fdisk  Commands  Using  fdisk  Command  m Use  fdisk  command  m,  to  view  all  available  fdisk  commands  as  shown  below. # fdisk /dev/sda The number of cylinders for this disk is set to 9729. There is nothing wrong with that, but this is larger than 1024, and could in certain setups cause problems with: 1) software that runs at boot time (e.g., old versions of LILO) 2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK) Command (m for help): m Command action a toggle a bootable flag b edit bsd disklabel c toggle the dos compatibility flag d delete a partition l list known partition types2  of  11 18  Apr  12  7:29  pm
  3. 3. 7  Linux  fdisk  Command  Examples  to  Manage  Hard  Disk  ParFFon hPp://www.thegeekstuff.com/2010/09/linux-­‐fdisk/ m print this menu n add a new partition o create a new empty DOS partition table p print the partition table q quit without saving changes s create a new empty Sun disklabel t change a partitions system id u change display/entry units v verify the partition table w write table to disk and exit x extra functionality (experts only) 3.  Delete  a  Hard  Disk  Par;;on  Using  fdisk  Command  d Let  us  assume  that  you  like  to  combine  several  parFFons  (for  example,  /dev/sda6,  /dev/sda7  and  /dev/sda8)  into  a  single  disk  parFFon. To  do  this,  you  should  first  delete  all  those  individual  parFFons,  as  shown  below. # fdisk /dev/sda The number of cylinders for this disk is set to 9729. There is nothing wrong with that, but this is larger than 1024, and could in certain setups cause problems with: 1) software that runs at boot time (e.g., old versions of LILO) 2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK) Command (m for help): p Disk /dev/sda: 80.0 GB, 80026361856 bytes 255 heads, 63 sectors/track, 9729 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0xf6edf6ed Device Boot Start End Blocks Id System /dev/sda1 1 1959 15735636 c W95 FAT32 (LBA) /dev/sda2 1960 5283 26700030 f W95 Extd (LBA) /dev/sda3 5284 6528 10000462+ 7 HPFS/NTFS /dev/sda4 6529 9729 25712032+ c W95 FAT32 (LBA) /dev/sda5 * 1960 2661 5638752 83 Linux /dev/sda6 2662 2904 1951866 83 Linux /dev/sda7 2905 3147 1951866 83 Linux /dev/sda8 3148 3264 939771 82 Linux swap / Solaris /dev/sda9 3265 5283 16217586 b W95 FAT32 Command (m for help): d Partition number (1-9): 8 Command (m for help): d Partition number (1-8): 7 Command (m for help): d Partition number (1-7): 6 Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. WARNING: Re-reading the partition table failed with error 16: Device or resource busy. The kernel still uses the old table. The new table will be used at3  of  11 18  Apr  12  7:29  pm
  4. 4. 7  Linux  fdisk  Command  Examples  to  Manage  Hard  Disk  ParFFon hPp://www.thegeekstuff.com/2010/09/linux-­‐fdisk/ the next reboot or after you run partprobe(8) or kpartx(8) Syncing disks. 4.  Create  a  New  Disk  Par;;on  with  Specific  Size  Using  fdisk  Command  n Once  you’ve  deleted  all  the  exisFng  parFFons,  you  can  create  a  new  parFFon  using  all  available  space  as  shown  below. # fdisk /dev/sda The number of cylinders for this disk is set to 9729. There is nothing wrong with that, but this is larger than 1024, and could in certain setups cause problems with: 1) software that runs at boot time (e.g., old versions of LILO) 2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK) Command (m for help): n First cylinder (2662-5283, default 2662): Using default value 2662 Last cylinder, +cylinders or +size{K,M,G} (2662-3264, default 3264): Using default value 3264 In  the  above  example,  fdisk  n  command  is  used  to  create  new  parFFon  with  the  specific  size.  While  creaFng  a  new  parFFon,  it  expects following  two  inputs. StarFng  cylinder  number  of  the  parFFon  to  be  create  (First  cylinder). Size  of  the  parFFon  (or)  the  last  cylinder  number  (Last  cylinder,  +cylinders  or  +size  ). Please  keep  in  mind  that  you  should  issue  the  fdisk  write  command  (w)  ader  any  modificaFons. Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. WARNING: Re-reading the partition table failed with error 16: Device or resource busy. The kernel still uses the old table. The new table will be used at the next reboot or after you run partprobe(8) or kpartx(8) Syncing disks. Ader  the  parFFon  is  created,  format  it  using  the  mkfs  command  as  shown  below. # mkfs.ext3 /dev/sda7 5.  View  the  Size  of  an  exis;ng  Par;;on  Using  fdisk  -­‐s As  shown  below,  fdisk  -­‐s  displays  the  size  of  the  parFFon  in  blocks. # fdisk -s /dev/sda7 4843566 The  above  output  corresponds  to  about  4900MB. 6.  Toggle  the  Boot  Flag  of  a  Par;;on  Using  fdisk  Command  a Fdisk  command  displays  the  boot  flag  of  each  parFFon.  When  you  want  to  disable  or  enable  the  boot  flag  on  the  corresponding parFFon,  do  the  following. If  you  don’t  know  why  are  you  are  doing  this,  you’ll  mess-­‐up  your  system.4  of  11 18  Apr  12  7:29  pm
  5. 5. 7  Linux  fdisk  Command  Examples  to  Manage  Hard  Disk  ParFFon hPp://www.thegeekstuff.com/2010/09/linux-­‐fdisk/ # fdisk /dev/sda The number of cylinders for this disk is set to 9729. There is nothing wrong with that, but this is larger than 1024, and could in certain setups cause problems with: 1) software that runs at boot time (e.g., old versions of LILO) 2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK) Command (m for help): p Disk /dev/sda: 80.0 GB, 80026361856 bytes 255 heads, 63 sectors/track, 9729 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0xf6edf6ed Device Boot Start End Blocks Id System /dev/sda1 1 1959 15735636 c W95 FAT32 (LBA) /dev/sda2 1960 5283 26700030 f W95 Extd (LBA) /dev/sda3 5284 6528 10000462+ 7 HPFS/NTFS /dev/sda4 6529 9729 25712032+ c W95 FAT32 (LBA) /dev/sda5 * 1960 2661 5638752 83 Linux /dev/sda6 3265 5283 16217586 b W95 FAT32 /dev/sda7 2662 3264 4843566 83 Linux Partition table entries are not in disk order Command (m for help): a Partition number (1-7): 5 Command (m for help): p Disk /dev/sda: 80.0 GB, 80026361856 bytes 255 heads, 63 sectors/track, 9729 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0xf6edf6ed Device Boot Start End Blocks Id System /dev/sda1 1 1959 15735636 c W95 FAT32 (LBA) /dev/sda2 1960 5283 26700030 f W95 Extd (LBA) /dev/sda3 5284 6528 10000462+ 7 HPFS/NTFS /dev/sda4 6529 9729 25712032+ c W95 FAT32 (LBA) /dev/sda5 1960 2661 5638752 83 Linux /dev/sda6 3265 5283 16217586 b W95 FAT32 /dev/sda7 2662 3264 4843566 83 Linux Partition table entries are not in disk order Command (m for help): As  seen  above,  the  boot  flag  is  disabled  on  the  parFFon  /dev/sda5. 7.  Fix  Par;;on  Table  Order  Using  fdisk  Expert  Command  f When  you  delete  a  logical  parFFon,  and  recreate  it  again,  you  might  see  the  “parFFon  out  of  order”  issue.  i.e  “ParFFon  table  entries  are not  in  disk  order”  error  message. For  example,  when  you  delete  three  logical  parFFons  (sda6,  sda7  and  sda8),  and  create  a  new  parFFon,  you  might  expect  the  new parFFon  name  to  be  sda6.  But,  the  system  might’ve  created  the  new  parFFon  as  sda7.  This  is  because,  ader  the  parFFons  are  deleted, sda9  parFFon  has  been  moved  as  sda6  and  the  free  space  is  moved  to  the  end.5  of  11 18  Apr  12  7:29  pm
  6. 6. 7  Linux  fdisk  Command  Examples  to  Manage  Hard  Disk  ParFFon hPp://www.thegeekstuff.com/2010/09/linux-­‐fdisk/ To  fix  this  parFFon  order  issue,  and  assign  sda6  to  the  newly  created  parFFon,  execute  the  expert  command  f  as  shown  below. $ fdisk /dev/sda The number of cylinders for this disk is set to 9729. There is nothing wrong with that, but this is larger than 1024, and could in certain setups cause problems with: 1) software that runs at boot time (e.g., old versions of LILO) 2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK) Command (m for help): p Disk /dev/sda: 80.0 GB, 80026361856 bytes 255 heads, 63 sectors/track, 9729 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0xf6edf6ed Device Boot Start End Blocks Id System /dev/sda1 1 1959 15735636 c W95 FAT32 (LBA) /dev/sda2 1960 5283 26700030 f W95 Extd (LBA) /dev/sda3 5284 6528 10000462+ 7 HPFS/NTFS /dev/sda4 6529 9729 25712032+ c W95 FAT32 (LBA) /dev/sda5 * 1960 2661 5638752 83 Linux /dev/sda6 3265 5283 16217586 b W95 FAT32 /dev/sda7 2662 3264 4843566 83 Linux Partition table entries are not in disk order Command (m for help): x Expert command (m for help): f Done. Expert command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. WARNING: Re-reading the partition table failed with error 16: Device or resource busy. The kernel still uses the old table. The new table will be used at the next reboot or after you run partprobe(8) or kpartx(8) Syncing disks. Once  the  parFFon  table  order  is  fixed,  you’ll  not  get  the  “ParFFon  table  entries  are  not  in  disk  order”  error  message  anymore. # fdisk -l Disk /dev/sda: 80.0 GB, 80026361856 bytes 255 heads, 63 sectors/track, 9729 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0xf6edf6ed Device Boot Start End Blocks Id System /dev/sda1 1 1959 15735636 c W95 FAT32 (LBA) /dev/sda2 1960 5283 26700030 f W95 Extd (LBA) /dev/sda3 5284 6528 10000462+ 7 HPFS/NTFS /dev/sda4 6529 9729 25712032+ c W95 FAT32 (LBA) /dev/sda5 * 1960 2661 5638752 83 Linux /dev/sda6 2662 3264 4843566 83 Linux /dev/sda7 3265 5283 16217586 b W95 FAT326  of  11 18  Apr  12  7:29  pm
  7. 7. 7  Linux  fdisk  Command  Examples  to  Manage  Hard  Disk  ParFFon hPp://www.thegeekstuff.com/2010/09/linux-­‐fdisk/ 1 Tweet 10 Like 4  Share  Comment If  you  enjoyed  this  ar;cle,  you  might  also  like.. 1. 50  Linux  Sysadmin  Tutorials Awk  IntroducFon  –  7  Awk  Print  Examples 2. 50  Most  Frequently  Used  Linux  Commands  (With  Examples) Advanced  Sed  SubsFtuFon  Examples 3. Top  25  Best  Linux  Performance  Monitoring  and  Debugging 8  EssenFal  Vim  Editor  NavigaFon  Fundamentals Tools 25  Most  Frequently  Used  Linux  IPTables  Rules 4. Mommy,  I  found  it!  –  15  PracFcal  Linux  Find  Command Examples Examples Turbocharge  PuTTY  with  12  Powerful  Add-­‐Ons 5. Linux  101  Hacks  2nd  EdiFon  eBook   {  12  comments…  read  them  below  or  add  one  } 1  anurag  rana  September  14,  2010  at  2:50  am thanxs  …… 2  anurag  rana  September  14,  2010  at  2:52  am sir  ,  you  provides  very  good  tuts….i  use  to  save  every  single  page  of  your  arFcles…  thanxs  again.. 3  Madharasan  September  14,  2010  at  4:57  am The  “Warning  Message”  in  this  arFcle  reminds  me  of  the  mistake  I  did  while  teaching  linux  to  a  group  of  students. I  was  about  to  enter  the  command  #  mkfs.ext3  /dev/sda4 But  unfortunately  just  when  I  have  finished  typing  #  mkfs.ext3  /dev/sda  ,  I  accidentely  pressed  the  enter  key…. There  ends  the  story  of  my  LINUX  OS  of  that  machine  and  my  session  on  Disk  management. Now  a  days,  I  first  enter  the  device  details  and  opFons,  only  then  the  command   Conclusion: No  Playing  with  linux,  at  Fmes  it  is  merciless 4  Chris  F.A.  Johnson  September  14,  2010  at  1:43  pm s/loose/lose/7  of  11 18  Apr  12  7:29  pm
  8. 8. 7  Linux  fdisk  Command  Examples  to  Manage  Hard  Disk  ParFFon hPp://www.thegeekstuff.com/2010/09/linux-­‐fdisk/ 5  DarkForce  September  14,  2010  at  5:21  pm Thanks  for  Fp  number  7. 6  Ramesh  Natarajan  September  14,  2010  at  8:51  pm @Chris, Thanks  for  poinFng  out  the  typo.  It’s  fixed. 7  jameslee  September  15,  2010  at  9:35  am thank  u  sir,its  very  useful 8  raralee  September  15,  2010  at  11:07  am good  Fps. how  to  add  new  space  on  the  exisFng  parFFon  using  fdisk  without  losing  data? 9  Sebas  September  16,  2010  at  12:46  pm Add  new  space  w/o  loosing  data  with  fdisk….?  i  think  that’s  not  posible. 10  madharasan  September  17,  2010  at  1:48  am @raralee resizing  a  parFFon  without  losing  data  is  not  possible. But  if  you  have  a  plan  already  that  you  would  be  changing  parFFon  sizes,  then  please  use  LVM  (  Logical  Volume  Manager  ) 11  alieblice  June  27,  2011  at  3:50  pm I  have  problem  with  fdisk  command when  i  tell  it  to  make  80  megabyte  drive  with  this  input  ((  +80M))  it  make  85  megabyte  drive  and  the  drive  is  made  by  vmware player  on  ubutnu  10.04 any  idea  why  this  happen  ? 12  Guus  August  29,  2011  at  10:56  am Thanks  a  lot! Ader  restoring  a  Windows  installaFon  to  a  new  harddisk,  i  found  that  i  had  made  a  mistake  with  the  parFFon-­‐order,  causing  a non-­‐boot.  Ader  reordering  the  parFFons,  it  boots  again  (although  i  won’t  use  it,  not  my  machine    . Leave  a  Comment Name E-­‐mail Website8  of  11 18  Apr  12  7:29  pm
  9. 9. 7  Linux  fdisk  Command  Examples  to  Manage  Hard  Disk  ParFFon hPp://www.thegeekstuff.com/2010/09/linux-­‐fdisk/  NoFfy  me  of  followup  comments  via  e-­‐mail Submit Previous  post:  6  Perl  File  Handle  Examples  to  Open,  Read,  and  Write  File Next  post:  VMWare  ESXi  4:  How  to  Add  Virtual  Hard  Disk  (from  Datastore)  to  a  VM  Using  vSphere  Client Sign  up  for  our  free  email  newslePer   you@address.com           Sign Up            RSS    TwiPer    Facebook   Search EBOOKS9  of  11 18  Apr  12  7:29  pm
  10. 10. 7  Linux  fdisk  Command  Examples  to  Manage  Hard  Disk  ParFFon hPp://www.thegeekstuff.com/2010/09/linux-­‐fdisk/ POPULAR  POSTS 12  Amazing  and  EssenFal  Linux  Books  To  Enrich  Your  Brain  and  Library 50  UNIX  /  Linux  Sysadmin  Tutorials 50  Most  Frequently  Used  UNIX  /  Linux  Commands  (With  Examples) How  To  Be  ProducFve  and  Get  Things  Done  Using  GTD 30  Things  To  Do  When  you  are  Bored  and  have  a  Computer Linux  Directory  Structure  (File  System  Structure)  Explained  with  Examples Linux  Crontab:  15  Awesome  Cron  Job  Examples Get  a  Grip  on  the  Grep!  –  15  PracFcal  Grep  Command  Examples Unix  LS  Command:  15  PracFcal  Examples 15  Examples  To  Master  Linux  Command  Line  History Top  10  Open  Source  Bug  Tracking  System Vi  and  Vim  Macro  Tutorial:  How  To  Record  and  Play Mommy,  I  found  it!  -­‐-­‐  15  PracFcal  Linux  Find  Command  Examples 15  Awesome  Gmail  Tips  and  Tricks 15  Awesome  Google  Search  Tips  and  Tricks RAID  0,  RAID  1,  RAID  5,  RAID  10  Explained  with  Diagrams Can  You  Top  This?  15  PracFcal  Linux  Top  Command  Examples Top  5  Best  System  Monitoring  Tools Top  5  Best  Linux  OS  DistribuFons How  To  Monitor  Remote  Linux  Host  using  Nagios  3.0 Awk  IntroducFon  Tutorial  –  7  Awk  Print  Examples How  to  Backup  Linux?  15  rsync  Command  Examples The  UlFmate  Wget  Download  Guide  With  15  Awesome  Examples Top  5  Best  Linux  Text  Editors Packet  Analyzer:  15  TCPDUMP  Command  Examples The  UlFmate  Bash  Array  Tutorial  with  15  Examples 3  Steps  to  Perform  SSH  Login  Without  Password  Using  ssh-­‐keygen  &  ssh-­‐copy-­‐id Unix  Sed  Tutorial:  Advanced  Sed  SubsFtuFon  Examples UNIX  /  Linux:  10  Netstat  Command  Examples The  UlFmate  Guide  for  CreaFng  Strong  Passwords 6  Steps  to  Secure  Your  Home  Wireless  Network Turbocharge  PuTTY  with  12  Powerful  Add-­‐Ons About  The  Geek  Stuff10  of  11 18  Apr  12  7:29  pm
  11. 11. 7  Linux  fdisk  Command  Examples  to  Manage  Hard  Disk  ParFFon hPp://www.thegeekstuff.com/2010/09/linux-­‐fdisk/  My  name  is  Ramesh  Natarajan.  I  will  be  posFng  instrucFon  guides,  how-­‐to,  troubleshooFng  Fps  and  tricks  on Linux,  database,  hardware,  security  and  web.  My  focus  is  to  write  arFcles  that  will  either  teach  you  or  help  you  resolve  a problem.  Read  more  about  Ramesh  Natarajan  and  the  blog. Support  Us Support  this  blog  by  purchasing  one  of  my  ebooks. Bash  101  Hacks  eBook Sed  and  Awk  101  Hacks  eBook Vim  101  Hacks  eBook Nagios  Core  3  eBook Contact  Us Email  Me  :  Use  this  Contact  Form  to  get  in  touch  me  with  your  comments,  quesFons  or  suggesFons  about  this  site.  You  can  also simply  drop  me  a  line  to  say  hello!. Follow  us  on  TwiPer Become  a  fan  on  Facebook     Copyright  ©  2008–2012  Ramesh  Natarajan.  All  rights  reserved  |  Terms  of  Service  |  AdverFse11  of  11 18  Apr  12  7:29  pm

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