Discussion on Linux partitioning knowledge _unix Linux

First of all, we want to make some preliminary understanding of the basic concept of hard disk partition, the partition of hard disk mainly divides into basic partition (primary partion) and expand partition (extension partion) two kinds, the sum of basic partition and expand partition cannot exceed four. The basic partition can be used immediately but cannot be partitioned. The extended partition must be partitioned before it can be used, which means it must also be partitioned two times. So what is it that is divided by the extended partition? It is the logical partition (logical partion), and the logical partition is not limited in number.

For users who are accustomed to using DOS or Windows, several partitions have several drives, and each partition is given an alphabetic identifier, which can then be used to specify the files and directories on the partition, and their file structure is independent and very well understood. But it's a bit annoying to start with Red Hat Linux for these users. Because for Red Hat Linux users, regardless of the number of partitions, to which directory to use, it ultimately has only one root directory, a separate and unique file structure. Each partition in Red Hat Linux is used to make up the entire filesystem, because it employs a processing method called "Load", which contains a complete set of files and directories and links a partition to a directory. A partition to load will make its storage space available in a directory. Now let's look at how Red Hat Linux drives are identified.

For IDE hard drives, the drive identifier is "hdx~", where "HD" indicates the type of device the partition is in, and this is the IDE hard drive. "X" is the disk number (A is the base disk, B is the basic subordinate disk, C is the secondary master disk, D is the secondary slave disk, "~" represents the partition, the first four partitions are numbers 1 through 4, they are primary or extended partitions, and logical partitions begin from 5. Example, Hda3 is represented as the third primary or extended partition on the first IDE hard disk, HDB2 as the second primary partition or extended partition on the second IDE hard disk. The SCSI hard drive is identified as "sdx~", the SCSI hard drive is "SD" to indicate the type of device the partition resides in, and the rest is the same as the IDE hard disk notation, not to say more.

As we can see from the above, Red Hat Linux partitions are different from other operating system partitions, its partition format is only ext2 and swap two kinds, ext2 for system files, swap as Red Hat Linux swap partition. Now we know that Red Hat Linux requires at least two dedicated partitions (Linux native and Linux swap) and that Red Hat Linux cannot be installed on the dos/windows partition. In general, we install Red Hat Linux with one or more hard disk partitions of type "Linux native", but each partition of Red Hat Linux must specify a "mount point" (Mount), telling Red Hat Linux to start , which directory you want to use for this directory. For a "swap" partition, the general definition is one and it is not necessary to define the mount point. Let's start with a preliminary understanding of "Linux native" and "Linux swap".

The *swap partition is the switched partition of the Linux temporary storage data, which mainly saves the data temporarily from the main memory, and then redeployment the memory when needed, and the partition used as swap does not need to specify "Mout point" (Mount), since it is used as a swap partition, We should certainly give it a size, it is at least equal to the amount of actual memory on the system, in general it is twice times the size of memory, if you are 16MB of memory, then the size of the swap partition is 32MB, and so on. But must also note that the swap partition should not be greater than 128MB, if you are 64MB of memory, then the largest swap partition can only be set to 127MB, and then large is wasted space, because the system does not require a large exchange partition. And so on, if you are 128MB or more memory, the swap partition can only be set to the maximum 127MB. What's more, you must be aware that if you are 128MB (or more) of memory, you must remind the system that you have such a large memory, otherwise it can not recognize you this 128MB memory. As follows: When the installation process is successfully started, a boot: Prompt is displayed, and you can simply type Boot:linux MEM=128MB. Alternatively, you can create and use more than one swap partition, up to 16.

*linux native is the place where system files are stored, and it can only be used with ext2 partition type, as mentioned above. For Windows users, the operating system must be installed in the same partition, is it commercial software! So you have no choice! For Red Hat Linux, you have a larger choice, you can put the system files in several areas to install (must describe the loading point), can also be installed in the same partition (loading point is "/"). Let's look at what partitions can be created (only a few are common).

/boot partition, it contains the kernel of the operating system and the files to be used during the boot system, and it is necessary to build this partition because most PCs are currently subject to BIOS limitations, and if there is a separate/boot boot partition, even if there is a problem with the primary root partition, The computer is still able to boot. The size of this partition is approximately between 50MB-100MB. But if you want to start the Red Hat Linux system with Lilo, the partitions containing the/boot must be completely below 1023 of the cylinder surface. And since the 8GB data lilo is unreadable, Red Hat Linux is installed within the 8GB area.

The/USR partition is where the Red Hat Linux system stores the software and, if possible, the maximum space should be allocated to it.

The/home partition is where the user's home directory is located, and the size of the partition depends on how many users are there. If it is a multi-user common use of a computer, this partition is completely necessary, and root users can also control the use of ordinary users of the computer, such as the user or user group to implement the limited use of hard disk, restricting the average user access to which files. In fact, single users also have the necessary to establish this zoning, because without this partition, then you can only be the root of the user's identity landing system, this is dangerous, because the root users of the system has absolute right to use, but once you have the system for the wrong operation, trouble will come.

The/var/log partition is the system logging partition, and if this separate partition is set up, it will not affect the primary partition of the operating system, even if there is a problem with the system's log files.

/tmp partition, for storing temporary files. This is necessary for multi-user systems or Web servers. This allows the other parts of the file system to be secure even if the program is running with a large number of temporary files, or if the user is doing something wrong with the system. Because this part of the file system is still subject to read and write operations, it usually occurs faster than other parts.

/bin partitions, storing standard system utilities.

/dev partition, storage device file.

/OPT partition, which holds optional installed software.

/sbin partitions, storing standard system management files.

Several common partitions are described above, and generally we need a swap partition, a/boot partition, A/USR partition, a/home partition, and a/var/log partition. Of course, there is no regulation, it is entirely in accordance with your personal to decide. But remember to have at least two partitions, one swap partition, one/partition. Now let's look at how to partition.

There are two partitioning tools that users can use:

1. Disk Druid: It is the hard drive management tool provided by Red Hat Linux, which was originally sold with Red hatlinux5, it can create and delete hard disk partitions according to user's requirements, and can also manage loading points for each partition, which is a good partitioning software, recommended to readers. The Red Hat Linux partition will also be described in detail in this article.

2. FDISK: It is the traditional Linux hard disk partitioning tool, more powerful than disk druid, and more flexible to use. However, Fdisk requires users to have some experience with the hard disk partition, and can adapt and read the simple text interface. If you're partitioning a hard drive for the first time, it's best to avoid a program like Fdisk, which is powerful but doesn't feel good.

Note: In addition, Red Hat Linux also provides a partition software called FIPS, but this zoning software is dangerous and it is not advisable to promote the operation. While many people have successfully partitioned their hard drives with FIPS, this does not guarantee that FIPS will function properly on your system. Also, Red Hat Linux does not provide FIPS support, and advises you to use this zoning software with great caution.

If you want to install Red Hat Linux on a disk that already contains other operating systems, that is, multiple operating systems, this is more complicated, because one error can destroy the data you have worked so hard to keep and make you cry without tears. If you want Red Hat Linux to coexist with OS/2, you must use OS/2 partition software to create a hard disk partition, or OS/2 will not recognize the hard drive partition. In addition, you can use some other zoning software to partition, listed below are some common such zoning tool software:

*partition Commander software, download from www.v-com.com.

*partition it software, download from www.quarterdeck..com.

*partition magic Software, download from www.powerquest.com.

Note: Hard disk partitioning is a very dangerous step, you want to safely without loss of data in the case of changing the partition of the disk is a bit unrealistic, so I recommend that you back up the important data, install more operating systems to do so, for the rainy. Of course, you may just install the system or ready to reload, that is another thing, but we must treat the partition should be prudent and prudent, remember.

Let's take a detailed look at some of the information contained in the disk Druid partition software of Red Hat linux7.1.

1. Current disk partitions area (where each row represents a hard disk partition)

mount point indicates that Red Hat Linux starts and runs after the partition's loading points, and swap space (Linux swap) does not require a mount point.

Device the device name of the hard disk partition

Requeted The minimum space to apply for this partition definition

Actual the actual space assigned to the partition

Type describes the types of the partition

2. Drive summaries area (each row here represents one hard drive)

Drive display the device name of the hard disk

GEOM[C/H/S] Displays the physical information of the hard disk, C (cylinder), H (head), S (sector)

Total shows free space on hard disk

Used Show allocated space on your hard disk

Free shows the space allocated at the end of the hard drive

Bar graph The bar graphically shows the percentage of the current hard disk usage, #号越少, the more free space

3. Disk Druid button

Add add one partition

Edit modifies the properties of the partition that is selected in current disk partitons, and selecting this button will appear with a dialog box to modify, but only the mount point of the partition can be modified. If you need to modify other content, please delete the section first and then rebuild the partition.

Delete Deletes a partition that is selected in the current disk partitons

OK confirm

Back does not save, return

4. If you want to add a section, please click the "Add" button, then a dialog box appears, the contents are as follows:

mount point partition mount points, description partition

Size partitions

Grow to fill disk indicates that this partition will fill the entire unallocated space of one hard drive. At this point, the capacity of this partition can be increased or decreased as other partitions are modified

Type select partition types

allowable drives Select which hard drive this partition will be created on

Well, through the above understanding presumably everyone can easily create a suitable partition. The next step we have to do is to format the partition, select the partition you want to format and press space, if you want to check for broken blocks when you format the partition, select Check for bad blocks during format, click OK and press the space key. If the partition has no data you want to save, it's best to format it.