Today belongs to talk about this topic commonplace, in recent years often have to ask readers (there are now more and more computer-free CD-ROM). Plus I want to literacy behind some "special Linux distribution," when the time comes to things certainly have to make a bootable U disk. So, starting today, a separate tutorial, talk about several different practice law.
Prior statement:
1. This article is for U disk, rather than external USB hard drive. External USB mobile hard disk is slightly different mode of operation, if a lot of people are interested in, then write another tutorial)
2. This article is about "U disk installation disk when" rather than "U disk to install the system" ( The two are completely different drops)
★ basic concept explained
Taking into account for the readers of this article, skill levels. For some newbie readers, I need to explain the basic concepts. If you think you are not a rookie, skip "to explain the basic concepts of" direct look at the following sections.
◇ CD image
The so-called "disc image" is actually a file, you can use a special burning software (together with "writable CD-ROM"), you can burn a CD image file.
There are several CD image format, the most common is the extension "ISO" format (the extension is derived from the ISO 9660 standard). CD image files provided by most operating systems are ISO format.
◇ What is "bootable" CD image?
"Bootable CD," also called a "bootable CD-ROM" (foreign language called "bootable"). These discs are then inserted into the CD-ROM drive, if you set in the BIOS "CD-ROM boot priority," then you can start the computer with this CD.
Similarly, the CD-ROM image can be divided into: two kinds of starts and not start. For example, some video storage / ISO music is not activated; for mounting the mirror system, must be started (obviously incorrect). So, if you want to make a bootable U disk, provided that you use the CD image itself is bootable.
◇ how to determine whether a bootable CD image?
I just said: Just a disc image file, not a physical disc. So you can not put it stuffed physical CD-ROM drive, use the virtual drive is not easy test. I recommend using virtual machine software testing. I never heard of a "virtual machine software," the students, before you can look at the tutorial "Literacy virtual machine operating system."
Test methods are as follows: first, to build an empty virtual system (Guest OS), set the image file you want to test the system in a virtual "drive", and then start the virtual system. If you can see the operating system of the relevant picture, it shows a successful start; if the screen goes black or English can not find the system prompt appears, it shows this image can not be started (can not boot).
◇ Hybrid mode
For bootable CD, there is a mode called "Hybrid Mode" (mixed mode). This mode of the optical disc, the disc may be directly physically burn, can also be produced directly as U disk bootable.
Today more and more operating system installation CD using "Hybrid Mode", which is convenient for everybody to make "U bootable disk." In addition, some discs, though not "Hybrid Mode", but can be converted into a "Hybrid mode" with the tool.
★ What is common production methods?
The so-called "common practice", that such methods CD nothing to do with the built-in system for most of the CD image (can be Windows system tray, can also be a Linux system disk, may be Apple's system tray).
However, the "general method" does not mean "universal method." Some of the old system (such as Win2000, WinXP) might not get the following ways. Old for this kind of system, you need to use special tools (taking into account the old system used less and less, so today temporarily chat).
Today, these three tools introduced, should be able to get:
the installation disk after WIndows Vista 1. (Vista, Win7, Win8)
2. all major Linux distributions (such as Debian, Ubuntu, RedHat, CentOS, Fedora, etc.)
3. Apple's installation disk
★ Why choose this several tools
To achieve "universal" tool has many purposes. I selected 3 models to introduce open source today. Why just pick open source? There are a few pay attention to the following:
As a result, I myself prefer the open source software (purely personal preference)
and secondly, open source software is free and do not need the registration code, no usage restrictions period (convenience).
Three to relatively closed-source software, the open source more reassuring (security).
I blog often see students should know, I was more concerned about "safe sex", so then the third point of a side note.
Bootable CD-ROM image production U disk, are mainly for loading system. If you are using authoring tool itself is not reliable (such as with a Trojan) will lead you make out of the launch of U disk is not safe, which led to the system you install it unsafe.
By the way tell you: why I do not like to use the U disk WinPE type of tool.
The first is the way of the limitations of PE - only for Windows systems (and now more and more users have started to play Linux or Mac OS).
Followed by a lot of PE tools are made in China, some domestic PE Tools like the "entrainment of smuggled goods." I do not complain, "Worship", it is a lot of domestic software rogue, using up not mind at ease.
★ rufus play (Windows platform)
rufus this tool, visibility is not too high, but the use of relatively cool (multi-interface customization options, and fast). Its official website in the "here."
Reminder: rufus exe file with a digital signature, so after downloading verify the digital signature is valid (to develop the good habit). Do not know how to verify the digital signature of the students, see the "Literacy file integrity check - on hash values and digital signatures."
This stuff Screenshots follows:
gone over the wall map, please
It will first before burning U disk format, so be sure to remember to check the "quick format." If you do not check this, it will be "full format." Now the motionless U disk has several GB, fully formatted to wait long.
★ UNetbootin play (cross-platform)
UNetbootin's official website in the "here." Home is beginning the download link three major platforms (Windows, Linux, Mac OS X) is.
Windows Screenshots follows:
gone over the wall map, please
This stuff is very simple to use, I see on the screenshot should be marked to understand.
★ dd play (cross-platform)
dd is a Linux / Unix commands a very useful, it can be used for "naked write" between the devices. The so-called "naked literacy" is - it does not ignore the file system, the file system directly over a physical device to read and write. It can do a lot of "copy command" (copy / cp) not dried or inconvenient to do things (such as backup / restore hard disk master boot sector). Today I talk about how to use dd to burn images to CD U disk.
Some students may be familiar with Linux will question, Linux cp command can also be used to burn iso image. Explain: This paper emphasizes the reason why the dd command, dd have also takes into account the portable version of Windows, and the Windows version of dd still be able to make the ISO image to the U disk.
◇ play on Linux / Unix is
Suppose you have an iso image file, path ~ / xxx.iso
Suppose you disk device corresponding to a U / dev / sdb
then you can use the following this command dd
dd bs = 4M if = ~ / xxx.iso of = / dev / sdb
Explain a little:
BS = parameter indicates the per-batch 4M bytes of data read 4MB (I usually use 4M, you can also use 8M, 2M or 1M).
if the path parameter indicates the input (file / device), here using a disc image file.
represents the path of the output parameter (file / device), as used herein is a U-disk.
Most Linux distributions have built-in command, so under normal circumstances, you do not need to install additional software packages you can use the dd command. After completion of the implementation of the dd command, remember to re-execute bit sync command sync disk cache before you pull out the U disk.
◇ play on Windows
dd command is also ported to the Windows system. Specifically go "here" to download. Pages long, the first half is to help you find the "Downloads for dd", you can see the download link.
It currently uses the 0.5 version (0.6 or beta, of sorts).
Dd under Windows, Linux usage with almost down. The only thing to note is that U disk "device path."
(Only one partition disk generally U) U disk you insert, if the letter is F: then the corresponding path is the device \\ \ f:.
If you iso image file on C: \ xxx.iso then use the following dd command to burn images to U-
dd = 4M IF BS = C: \ XXX.iso of \\ = \ F:.
(parameter explained earlier, here it further ado)
★ compare the advantages and disadvantages
To summarize the advantages and disadvantages of the three methods.
◇ compatibility
For U disk creation tools, compatibility is very important. Compatibility is not good, it may lead to burn U disk can not be started.
rufus UNetbootin compatibility and better than dd. dd drawback is that: If a mirror is not itself a hybrid mode (hybrid interpretation, said beginning of this article), with burning after dd will not start. Rufus, and the corresponding process may be performed UNetbootin in U-burning time.
To address this shortcoming dd, there is a remedy:
For Linux / Unix platforms, the first use isohybrid command to convert the iso image to a hybrid mode (the command is on SysLinux / ISOLinux package). Assuming your CD image is located in ~ / xxx.iso then use the following command to convert :( Unfortunately, this command has no windows version)
isohybrid ~ / xxx.iso
As rufus UNetbootin and contrast, and I personally feel that not only is superior rufus UNetbootin, but also better than some other tools (such as Universal USB Installer). I have come across: a single ISO image, the same physical disk U, with burning after UNetbootin not start, and you can start to burn after rufus.
◇ speed
dd fastest (I said earlier, dd is "naked read-write", the speed). rufus faster than UNetbootin (there are several different tools velocity contrast on the official website interface rufus)
◇ ease of use
UNetbootin and rufus almost - has a fool graphical interface.
dd ease the worst - you have to use the command line
◇ cross-platform
UNetbootin better than dd better than rufus (rufus Windows version only)
reminder:
here that the "cross-platform" refers to the tool itself, rather than out of the CD-ROM production. For example, rufus Although only the Windows version, but rufus can make Linux installation disk.
