使用磁盘实用程序创建RAID 1（镜像）阵列

一个突袭1array contains the same set of data on two or more disks. Also known as a mirrored array, RAID 1 one of the Redundant Array of Independent Disks (RAID) levels supported by OS X and磁盘实用程序。In a RAID 1 array, you assign two or more disks as a mirrored set.After you create the mirrored set, your Mac sees it as a single disk drive.

When your Mac writes data to the mirrored set, it duplicates the data across all members of the set to ensure that the data is protected against loss if any hard drive in the RAID 1 set fails. As long as any single member of the set remains functional, your Mac continues to operate normally, giving you complete access to your data.

您可以删除defective hard drivefrom a RAID 1 set and代替它带有新的或修复的硬盘驱动器。然后，RAID 1集对自己进行重建，将现有集合的数据复制到新成员。您可以在重建过程中继续使用Mac，因为它发生在后台。

Why RAID 1 Isn't a Backup

Although it is commonly used as part of a backup strategy, RAID 1 by itself is not an effective substitute for备份your data.

任何写给RAID 1集的数据都会立即复制给该集合的所有成员；删除文件时也是如此。一旦删除文件，该文件就会从RAID 1集的所有成员中删除。结果，RAID 1不允许您恢复旧版本的数据，例如您上周编辑的文件的版本。

Why Use a RAID 1 Mirror

Using a RAID 1 mirror as part of your backup strategy ensures maximum uptime and reliability. You can use RAID 1 for your startup drive, a data drive, or your backup drive.

创建RAID 1镜子需要的东西

To create a RAID 1 mirror for your Mac, you need a few basic components.

• OS X Leopard（10.5）通过OS X优胜美地（10.10）。
• 磁盘实用程序, which is included withOS X。
• Two or more hard drives.创建RAID 1镜像集的过程删除了硬盘驱动器上的所有数据。建议使用相同的品牌和型号的硬盘驱动器，但不需要。
• 一个或多个驱动器外壳。Mac Pro用户可能具有内部驱动器托架。其他所有人都需要一个或多个外部驱动器外壳。如果您使用多个驱动器外壳，则理想情况下应该是相同的品牌和型号，或者至少具有相同类型的接口，例如Firewire，USB，，，，霹雳，或SATA。

The process of creating a RAID set is relatively simple and doesn't take much time, but erasing all the drives in the RAID set using the Zero Out Data option is a time-consuming process that ensures maximum reliability.

Erase the Drives

The hard drives you use as members of the RAID 1 mirror set must first be erased.

因为您正在构建RAID 1集，以便您的数据始终保持访问，请花一点时间，并使用Disk Utility的安全性选项之一，零数据, which erases each hard drive. When you zero out data, you force the hard drive to check forbad data blocksduring the erasure process and to mark any bad blocks as not to be used. This decreases the likelihood of losing data due to a failing block on the hard drive. It also significantly increases the amount of time it takes to erase the drives from a few minutes to an hour or more per drive.

Erase the Drives Using the Zero Out Data Option

Erase each of the drives you plan to use in the RAID 1 mirror set.

1. 将您打算使用的硬盘驱动器连接到Mac并为其供电。

2. 发射磁盘实用程序， 位于申请>公用事业。

3. 从左窗格中的列表中选择要在RAID 1镜设置中使用的硬盘驱动器之一。确保选择驱动器，而不是驱动器名称下缩进的卷名。

   

4. 点击Erase标签。

   

5. 来自Volume Format下拉菜单，选择Mac OS X扩展（日记）作为要使用的格式。

   

6. 输入卷的名称。

   

7. 点击安全选项。

   

8. 选择零数据security option and then click好的。

9. 点击Erase。

   

10. Repeat steps 3 through 9 for each additional hard drive that is going to be part of the RAID 1 mirror set. Give each hard drive a unique name.

创建RAID 1镜子集

After you erase the drives you plan to use for the RAID 1 set, you're ready to start building the mirror set.就是这样：

1. 发射磁盘实用程序如果该应用程序尚未打开。

2. 选择您计划在RAID 1镜子中使用的硬盘驱动器之一Drive/Volume在磁盘实用程序窗口的左窗格中列出。

   

3. 点击袭击标签。

   

4. Enter a name for the RAID 1 mirror set. This is the name that displays on the desktop.

   

5. 选择Mac OS Extended (Journaled)来自Volume Format下拉式菜单。

   

6. 选择镜像突袭集as the突袭类型。

   

7. 点击选项。

   

8. 设置RAID块大小。块大小取决于您计划存储在RAID 1镜像集中的数据类型。为了进行一般使用，请考虑一个块大小，例如256K或更大，以优化RAID的性能。

9. 选择Automatically Rebuild RAID mirror set为了the RAID 1 mirror set you are creating to automatically rebuild itself if the members of the RAID become out of sync.

   One of the few times automatic building may not be a good idea is when you use the RAID 1 mirror set for data-intensive applications. Even though it's performed in the background, rebuilding a RAID mirror set uses significant处理器resources and may affect your use of the Mac.

10. Make your choices on the options and click好的。

11. 点击+(plus sign) to add the RAID 1 mirror set to the list of RAID arrays.

Add Slices (Hard Drives) to Your RAID 1 Mirror Set

现在，RAID 1镜子集在RAID阵列列表中可用，是时候将成员或切片添加到集合中了。

1. Drag one of the hard drives from the left pane of Disk Utility onto the RAID array name you created. Repeat this for each drive you want to add to the RAID 1 mirror set. A minimum of two slices, or hard drives, is required for a mirrored RAID. After you add all the hard drives to the RAID 1 mirror set, you are ready to create the finished RAID volume for your Mac to use.

2. 点击创造。

   

3. 一个Creating RAID警告表下降以提醒您，构成RAID阵列的驱动器上的所有数据将被删除。点击创造接着说。

在创建RAID 1 Mirror集合期间，磁盘实用程序将个人命名为卷that make up the RAID set to "RAID Slice." It then creates the actual RAID 1 mirror set and mounts it as a normal hard drive volume on your Mac's desktop.

您创建的RAID 1镜像集的总容量等于集合的最小成员，减去RAID引导文件和数据结构的开销。

现在，您可以关闭磁盘实用程序，并使用RAID 1镜集，就像Mac上的其他磁盘卷一样。

使用您的新突袭1镜套

OS X treats RAID sets created with Disk Utility as if they are standard hard drive volumes. As a result, you can use them as startup volumes, data volumes, or backup volumes.

Now that you have finished creating the RAID 1 mirror set, here are some tips for its use.

热备件

You can add additional volumes to a RAID 1 mirror at any time, even long after the RAID array is created. Drives added after a RAID array is created are known as hot spares. The RAID array doesn't use hot spares unless an active member of the set fails. At that point, the RAID array automatically uses a hot spare as a replacement for the failed hard drive and automatically starts a rebuilding process to convert the hot spare to an active member of the array. When you add a hot spare, the hard drive must be equal to or larger than the smallest member of the RAID 1 mirror set.

重建

Rebuilding can occur any time one of the RAID 1 mirror set drives becomes out of sync—the data on a drive doesn't match other members of the set. When this occurs, the rebuilding process begins automatically, assuming you selected the automatic rebuild option during the RAID 1 mirror set creation process. During the rebuilding process, the out-of-sync disk has data restored to it from the remaining members of the set.

The rebuilding process takes time. While you can continue to use your Mac as usual during the rebuild, you should not睡觉or shut down the Mac during the process.

Rebuilding can occur for reasons beyond a hard drive failure. Some common events that trigger a rebuild are an OS X crash, a power failure, or improperly turning off the Mac.