Documentation/Filesystem_ext3的中文翻译

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Documentation/Filesystem_ext3 的中文翻译

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Ext3 Filesystem

Ext3（Thirdextendedfilesystem）名词释义Ext3是一种日志式文件系统，是对ext2系统的扩展，它兼容ext2。

===============

Ext3 was originally released in September 1999. Written by Stephen Tweedie

for the 2.2 branch, and ported to 2.4 kernels by Peter Braam, Andreas Dilger,

Andrew Morton, Alexander Viro, Ted Ts'o and Stephen Tweedie.

Ext3 is the ext2 filesystem enhanced with journalling capabilities.

Options

Ext3最初发布是在1999年的九月。作者：斯蒂芬·特威迪2.2分支，并移植到2.4内核由彼得·布拉姆，安德烈亚斯，

安德鲁·莫顿，亚历山大，Ted Ts'o和斯蒂芬·特威迪。

ext3是ext2文件系统的日志功能增强。

选项

=======

When mounting an ext3 filesystem, the following option are accepted:

安装ext3文件系统时，以下选项被接受：

(*) == default

ro Mount filesystem read only. Note that ext3 will replay

the journal (and thus write to the partition) even when

mounted "read only". Mount options "ro,noload" can be

used to prevent writes to the filesystem.

只读的安装文件系统。需要注意的是ext3的重播日志（从而写入到该分区）甚至当

安装“只读”。可以用来防止写入文件系统的挂载选项“ro,noload”。

journal=update Update the ext3 file system's journal to the current

format.

更新为当前格式的ext3文件系统的日志。

journal=inum When a journal already exists, this option is ignored.

Otherwise, it specifies the number of the inode which

will represent the ext3 file system's journal file.

当一个日志已经存在，此选项被忽略。否则，它指定的i节点数目

将代表ext3文件系统的日志文件。

journal_dev=devnum When the external journal device's major/minor numbers

have changed, this option allows the user to specify

the new journal location. The journal device is

identified through its new major/minor numbers encoded

in devnum.

当外部的日志设备的主要/次要号码有改变，这个选项允许用户指定

新日志位置。日志设备通过其新的主要/次要号码编码识别在DEVNUM。

norecovery Don't load the journal on mounting. Note that this forces

不要加载日志在装入的时候。注意这个细节

noload mount of inconsistent filesystem, which can lead to

various problems.

挂载文件系统的不一致，这可能会导致各种各样的问题。

data=journal All data are committed into the journal prior to being

written into the main file system.

所有的数据都提交到日志之前被写入主文件系统。

data=ordered (*) All data are forced directly out to the main file

system prior to its metadata being committed to the

journal.

(*) 所有的数据都被迫直接向主文件致力于系统之前，它的元数据

日志。

data=writeback Data ordering is not preserved, data may be written

into the main file system after its metadata has been

committed to the journal.

不保留数据排序，数据可以被写入后的元数据一直到主文件系统

致力于到日志中。

commit=nrsec (*) Ext3 can be told to sync all its data and metadata

every 'nrsec' seconds. The default value is 5 seconds.

This means that if you lose your power, you will lose

as much as the latest 5 seconds of work (your

filesystem will not be damaged though, thanks to the

journaling). This default value (or any low value)

will hurt performance, but it's good for data-safety.

Setting it to 0 will have the same effect as leaving

it at the default (5 seconds).

Setting it to very large values will improve

performance.

(*) EXT3可以告诉所有的数据和元数据同步每‘nrsec’秒。默认值是5秒。

这意味着，如果你失去了你的电源，你将失去最新的5秒的工作一样多

（你的文件系统不会损坏，这要归功于日志）。此默认值（或任意低的

数值）会损害性能，但它的数据安全性好。将其设置为0，与设置为缺省

值（5秒）将有相同的效果。

将其设置为非常大的值将提高性能。

barrier=<0|1(*)> This enables/disables the use of write barriers in

这功能是启用/禁止使用写障碍。

barrier (*) the jbd code. barrier=0 disables, barrier=1 enables.

这个JBD代码。barrier=0 禁止， barrier=1 启用

nobarrier This also requires an IO stack which can support

barriers, and if jbd gets an error on a barrier

write, it will disable again with a warning.

Write barriers enforce proper on-disk ordering

of journal commits, making volatile disk write caches

safe to use, at some performance penalty. If

your disks are battery-backed in one way or another,

disabling barriers may safely improve performance.

The mount options "barrier" and "nobarrier" can

also be used to enable or disable barriers, for

consistency with other ext3 mount options.

这也需要一个可以支持障碍的IO堆栈，如果，JBD得到

一个错误在一个屏障写，它将被禁止同时伴有一次警告。

写障碍，执行适当的磁盘上的日志订购承诺，使挥发性磁

盘写入缓存安全地使用，在一些性能损失。如果你的磁盘

在这种或那种方式是电池供电的,禁用障碍，可以安全地提

高性能。挂载选项“barrier”和“nobarrier”的，也可用于

启用或禁用的障碍,与其他的ext3挂载选项的一致性。

user_xattr Enables Extended User Attributes. Additionally, you

need to have extended attribute support enabled in the

kernel configuration (CONFIG_EXT3_FS_XATTR). See the

attr(5) manual page and http://acl.bestbits.at/ to

learn more about extended attributes.

启用扩展的用户属性。此外，你需要获得在内核配置扩展属性

支持 (CONFIG_EXT3_FS_XATTR).请参阅了attr（5）手册页和

http://acl.bestbits.at/了解更多有关扩展属性。

nouser_xattr Disables Extended User Attributes.

禁用扩展用户属性。

acl Enables POSIX Access Control Lists support.

Additionally, you need to have ACL support enabled in

the kernel configuration (CONFIG_EXT3_FS_POSIX_ACL).

See the acl(5) manual page and http://acl.bestbits.at/
for more information.

启用POSIX访问控制列表的支持。此外，您需要启用ACL支持

在内核配置（CONFIG_EXT3_FS_POSIX_ACL）的。有关更多信息，

请参见ACL（5）手册页和http://acl.bestbits.at/的。

noacl This option disables POSIX Access Control List

support.

此选项禁用POSIX访问控制列表的支持。

reservation

noreservation

bsddf (*) Make 'df' act like BSD.

minixdf Make 'df' act like Minix.

(*) 做'DF'像BSD行为。

做'DF'像Minix行为。

check=none Don't do extra checking of bitmaps on mount.

不要做额外的检查安装位图。

nocheck

debug Extra debugging information is sent to syslog.

额外调试信息发送到syslog。

errors=remount-ro Remount the filesystem read-only on an error.

重新挂载文件系统只读方式发生错误的时候。

errors=continue Keep going on a filesystem error.

在文件系统上的错误继续下去。

errors=panic Panic and halt the machine if an error occurs.

(These mount options override the errors behavior

specified in the superblock, which can be

configured using tune2fs.)

恐吓和暂停机器，如果发生错误。(这些覆盖错误行为

的安装选项被指定在超级块中，它可以使用tune2fs配

置)。

data_err=ignore(*) Just print an error message if an error occurs

in a file data buffer in ordered mode.

只是打印一条错误消息_如果发生的错误在一个文件中

的数据缓冲区在有序模式。

data_err=abort Abort the journal if an error occurs in a file

data buffer in ordered mode.

中止该日志在一个错误出现在一个文件缓冲区的有序

模式下。

grpid Give objects the same group ID as their creator.

给对象相同组ID作为他们的创造者。

bsdgroups

nogrpid (*) New objects have the group ID of their creator.

(*) 新的对象有他们的创造者的组ID。

sysvgroups

resgid=n The group ID which may use the reserved blocks.

resuid=n The user ID which may use the reserved blocks.

组ID可以使用保留块。

sb=n Use alternate superblock at this location.

使用备用超级块在这个位置。

quota These options are ignored by the filesystem. They

noquota are used only by quota tools to recognize volumes

grpquota where quota should be turned on. See documentation

usrquota in the quota-tools package for more details

(http://sourceforge.net/projects/linuxquota).

忽略这些选项的文件系统。他们只使用配额工具来识别卷

在配额开启的时候。配额工具包的更多详细信息，请参阅

文档(http://sourceforge.net/projects/linuxquota).

jqfmt=<quota type> These options tell filesystem details about quota

usrjquota=<file> so that quota information can be properly updated

grpjquota=<file> during journal replay. They replace the above

quota options. See documentation in the quota-tools

package for more details

(http://sourceforge.net/projects/linuxquota).

这些选项告诉配额的文件系统的详细信息，使配额信息日志

重播期间得到正确更新。他们替换上面的配额选项。配额工具包、

的更多详细信息，请参阅文档

(http://sourceforge.net/projects/linuxquota).

Specification

=============

Ext3 shares all disk implementation with the ext2 filesystem, and adds

transactions capabilities to ext2. Journaling is done by the Journaling Block

Device layer.

EXT3部分的所有磁盘执行的ext2文件系统，并增加了事务功能的ext2。日志是通过日志块

设备层。

Journaling Block Device layer

-----------------------------

The Journaling Block Device layer (JBD) isn't ext3 specific. It was designed

to add journaling capabilities to a block device. The ext3 filesystem code

will inform the JBD of modifications it is performing (called a transaction).

The journal supports the transactions start and stop, and in case of a crash,

the journal can replay the transactions to quickly put the partition back into

a consistent state.

日志块设备层（JBD）不是ext3的特定。它被设计为块设备添加日志功能。ext3文件系统代码

将通知JBD的修改，它正在执行（称为一个事务处理）。该日志支持以启动和停止事务，在系

统崩溃的情况下，该日志可以重新执行交易尽快将该分区恢复一致的状态。

Handles represent a single atomic update to a filesystem. JBD can handle an

external journal on a block device.

句柄代表一个原子更新文件系统。JBD可以处理外部日志在块设备上。

Data Mode

数据模式

---------

There are 3 different data modes:

有3种不同的数据模式：

* writeback mode

In data=writeback mode, ext3 does not journal data at all. This mode provides

a similar level of journaling as that of XFS, JFS, and ReiserFS in its default

mode - metadata journaling. A crash+recovery can cause incorrect data to

appear in files which were written shortly before the crash. This mode will

typically provide the best ext3 performance.

*回写模式

In data=writeback mode，Ext3并没有所有的日志数据。此模式提供类似级别的日志的XFS，

JFS，ReiserFS文件系统在默认模式 - 元数据日志。崩溃+复苏可能会导致不正确的数据在

文件中出现极端的时间崩溃之前。这种模式通常会提供最好的ext3的性能。

* ordered mode

In data=ordered mode, ext3 only officially journals metadata, but it logically

groups metadata and data blocks into a single unit called a transaction. When

it's time to write the new metadata out to disk, the associated data blocks

are written first. In general, this mode performs slightly slower than

writeback but significantly faster than journal mode.

*有序模式

In data=ordered mode，ext3的正式日志的元数据，但逻辑分组到一个单元中的元数据和数据块

称为事务。当是来写新的元数据到磁盘上的时候，相关的数据块先写。在一般情况下，这种模式

下的性能略慢于回写，但速度比日志模式快很多。

* journal mode

data=journal mode provides full data and metadata journaling. All new data is

written to the journal first, and then to its final location.

In the event of a crash, the journal can be replayed, bringing both data and

metadata into a consistent state. This mode is the slowest except when data

needs to be read from and written to disk at the same time where it

outperforms all other modes.

* 日志模式

data=journal mode 提供了完整的数据和元数据日志。所有新的数据都先被写入该日志，

然后到它的最终位置。在系统崩溃的情况下，日志可以被重放，使数据和元数据到达一

个一致的状态。这种模式是最慢的，当数据需要读取和写入磁盘的同时，它优于所有其他模式

Compatibility

兼容性

-------------

Ext2 partitions can be easily convert to ext3, with `tune2fs -j <dev>`.

Ext3 is fully compatible with Ext2. Ext3 partitions can easily be mounted as

Ext2.

ext2分区可以很容易地转换为ext3分区，用`tune2fs -j <dev>`.EXT3完全兼容Ext2.ext3

分区可以很容易地安装Ext2。

External Tools

外部工具

==============

See manual pages to learn more.

请参阅手册页了解更多信息。

tune2fs: create a ext3 journal on a ext2 partition with the -j flag.

创建一个 ext3日志在一个ext2分区带有-j标志。

mke2fs: create a ext3 partition with the -j flag.

创建一个ext3分区带有-j标志。

debugfs: ext2 and ext3 file system debugger.

ext2和ext3文件系统的调试。

ext2online: online (mounted) ext2 and ext3 filesystem resizer

在线（安装）ext3和ext2文件系统大小调整

References

参考文献

==========

kernel source: <file:fs/ext3/>

<file:fs/jbd/>

内核源代码：<file:fs/ext3/>

<file:fs/jbd/>

programs: http://e2fsprogs.sourceforge.net/

http://ext2resize.sourceforge.net

程序： http://e2fsprogs.sourceforge.net/

http://ext2resize.sourceforge.net

useful links: http://www.ibm.com/developerworks/library/l-fs7/index.html
http://www.ibm.com/developerworks/library/l-fs8/index.html
有用的链接: http://www.ibm.com/developerworks/library/l-fs7/index.html
http://www.ibm.com/developerworks/library/l-fs8/index.html