{"id":867,"date":"2015-08-07T15:04:04","date_gmt":"2015-08-07T22:04:04","guid":{"rendered":"http:\/\/homepages.uc.edu\/~yaozo\/wordpress\/?p=867"},"modified":"2015-08-07T15:04:04","modified_gmt":"2015-08-07T22:04:04","slug":"linux-partition-howto","status":"publish","type":"post","link":"https:\/\/zhuoyao.net\/index.php\/2015\/08\/07\/linux-partition-howto\/","title":{"rendered":"Linux Partition HOWTO"},"content":{"rendered":"

5. Partitioning with fdisk<\/h1>\n

This section shows you how to actually partition your hard drive with the fdisk<\/b> utility. Linux allows only 4 primary partitions. You can have a much larger number of logical partitions by sub-dividing one of the primary partitions. Only one of the primary partitions can be sub-divided.<\/p>\n

Examples:<\/em><\/p>\n

    \n
  1. Four primary partitions (see Section 5.2<\/a>)<\/li>\n
  2. Mixed primary and logical partitions (see Section 5.3<\/a>)<\/li>\n<\/ol>\n
    \n

    <\/a>5.1. fdisk usage<\/h2>\n

    fdisk<\/b> is started by typing (as root) <\/b>fdisk<\/b> <\/tt>device<\/i><\/tt> at the command prompt. device<\/i><\/tt> might be something like \/dev\/hda<\/tt> or \/dev\/sda<\/tt> (see Section 2.1.1<\/a>). The basic fdisk<\/b> commands you need are:<\/p>\n

    p<\/b><\/tt> print the partition table<\/p>\n

    n<\/b><\/tt> create a new partition<\/p>\n

    d<\/b><\/tt> delete a partition<\/p>\n

    q<\/b><\/tt> quit without saving changes<\/p>\n

    w<\/b><\/tt> write the new partition table and exit<\/p>\n

    Changes you make to the partition table do not take effect until you issue the write (w) command. Here is a sample partition table:<\/p>\n\n\n\n
    \n
    Disk \/dev\/hdb: 64 heads, 63 sectors, 621 cylinders\nUnits = cylinders of 4032 * 512 bytes\n \n   Device Boot    Start       End    Blocks   Id  System\n\/dev\/hdb1   *         1       184    370912+  83  Linux\n\/dev\/hdb2           185       368    370944   83  Linux\n\/dev\/hdb3           369       552    370944   83  Linux\n\/dev\/hdb4           553       621    139104   82  Linux swap\n<\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    The first line shows the geometry of your hard drive. It may not be physically accurate, but you can accept it as though it were. The hard drive in this example is made of 32 double-sided platters with one head on each side (probably not true). Each platter has 621 concentric tracks. A 3-dimensional track (the same track on all disks) is called a cylinder. Each track is divided into 63 sectors. Each sector contains 512 bytes of data. Therefore the block size in the partition table is 64 heads * 63 sectors * 512 bytes er…divided by 1024. (See 4<\/a> for discussion on problems with this calculation.) The start and end values are cylinders.<\/div>\n
    \n
    <\/a>5.2. Four primary partitions<\/h2>\n
    The overview:<\/em><\/p>\n
    Decide on the size of your swap space (see Section 4.4<\/a>) and where it ought to go (see Section 4.4.3<\/a>). Divide up the remaining space for the three other partitions.<\/p>\n
    Example:<\/p>\n
    I start fdisk from the shell prompt:<\/p>\n\n\n\n
    \n
    # <\/b>fdisk<\/b> <\/tt>\/dev\/hdb<\/tt> \n<\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    which indicates that I am using the second drive on my IDE controller. (See Section 2.1<\/a>.) When I print the (empty) partition table, I just get configuration information.<\/p>\n\n\n\n
    \n
    Command (m for help): p<\/b><\/tt>\n\nDisk \/dev\/hdb: 64 heads, 63 sectors, 621 cylinders\nUnits = cylinders of 4032 * 512 bytes\n<\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    I knew that I had a 1.2Gb drive, but now I really know: 64 * 63 * 512 * 621 = 1281982464 bytes. I decide to reserve 128Mb of that space for swap, leaving 1153982464. If I use one of my primary partitions for swap, that means I have three left for ext2 partitions. Divided equally, that makes for 384Mb per partition. Now I get to work.<\/p>\n\n\n\n
    \n
    Command (m for help): n<\/b><\/tt>\nCommand action\n   e   extended\n   p   primary partition (1-4)\np<\/b><\/tt>\nPartition number (1-4): 1<\/b><\/tt>\nFirst cylinder (1-621, default 1):<RETURN><\/b><\/tt>\nUsing default value 1\nLast cylinder or +size or +sizeM or +sizeK (1-621, default 621): +384M<\/b><\/tt>\n<\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    Next, I set up the partition I want to use for swap:<\/p>\n\n\n\n
    \n
    Command (m for help): n<\/b><\/tt>\nCommand action\n   e   extended\n   p   primary partition (1-4)\np\nPartition number (1-4): 2<\/b><\/tt>\nFirst cylinder (197-621, default 197):<RETURN><\/b><\/tt>\nUsing default value 197\nLast cylinder or +size or +sizeM or +sizeK (197-621, default 621): +128M<\/b><\/tt>\n<\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    Now the partition table looks like this:<\/p>\n\n\n\n
    \n
       Device Boot    Start       End    Blocks   Id  System\n\/dev\/hdb1             1       196    395104   83  Linux\n\/dev\/hdb2           197       262    133056   83  Linux\n<\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    I set up the remaining two partitions the same way I did the first. Finally, I make the first partition bootable:<\/p>\n\n\n\n
    \n
    Command (m for help): a<\/b><\/tt>\nPartition number (1-4): 1<\/b><\/tt>\n<\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    And I make the second partition of type swap:<\/p>\n\n\n\n
    \n
    Command (m for help): t<\/b><\/tt>\nPartition number (1-4): 2<\/b><\/tt>\nHex code (type L to list codes): 82<\/b><\/tt>\nChanged system type of partition 2 to 82 (Linux swap)      \nCommand (m for help): p<\/b><\/tt>\n<\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    The end result:<\/p>\n\n\n\n
    \n
    Disk \/dev\/hdb: 64 heads, 63 sectors, 621 cylinders\nUnits = cylinders of 4032 * 512 bytes\n \n   Device Boot    Start       End    Blocks   Id  System\n\/dev\/hdb1   *         1       196    395104+  83  Linux\n\/dev\/hdb2           197       262    133056   82  Linux swap\n\/dev\/hdb3           263       458    395136   83  Linux\n\/dev\/hdb4           459       621    328608   83  Linux          \n<\/pre>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    Finally, I issue the write command (w) to write the table on the disk.Side topics:<\/p>\n