第13页

2K 1 2K 2K 2K 3.23K 6.47M 6.47M 6.47M 1 2K 2K 2K 2K 3.23K 6.47M 6.47M 6.47M

8K 1 128K 5K 5K 13.9K 1.74G 69.5M 69.5M 8K 1 128K 5K 5K 13.9K 1.74G 69.5M 69.5M

Total 2.63M 277G 218G 225G 3.22M 337G 263G 270G共有2.63M 277G 218G 225克3.22M 337G 263G 270G

dedup = 1.20, compress = 1.28, copies = 1.03, dedup = 1.20，压缩= 1.28，副本= 1.03，

dedup * compress / copies = 1.50 dedup *压缩/份= 1.50

Does the Server Have Enough Memory Installed to Undertake Deduplication?服务器是否有足够的内存安装进行重复数据删除呢？
The reason this question needs to be answered is that the deduplication tables consume memory and eventually spill over and consume disk space.需要回答这个问题的原因是，重复数据删除表中消耗内存，并最终溢出，占用磁盘空间。 At that point, ZFS has to perform extra read and write operations for every block of data on which deduplication is attempted.在这一点上，ZFS执行额外的每块上的重复数据删除是企图数据读取和写入操作。 This causes a reduction in performance.这会导致性能降低。

Furthermore, the cause of the performance reduction will be difficult to determine if you are unaware that deduplication is active and can have adverse effects.此外，性能降低的原因难以确定的，如果你不知道，重复数据删除是积极的，并可以产生不利影响。 A system that has large pools with small memory areas will not perform deduplication well.系统具有大池，小的内存区域不会执行重复数据删除。 Some operations, such as removing a large file system with dedup enabled, will severely decrease system performance if the system doesn"t meet the memory requirements.某些操作，如删除一个大的文件dedup dedup启用，将严重降低系统性能，如果系统不能满足对内存的要求。

Calculate memory requirement as follows:计算内存要求如下：

 Each in-core deduplication table (DDT) entry is approximately 320 bytes.每个核心的重复数据删除表（DDT）项约320个字节。

 Multiply the number of allocated blocks by 320.分配的块数乘以320。

Here"s an example using the data from the zdb information in Listing 1:下面是一个例子， zdb ZDB在清单1中的信息从数据：

In-core DDT size (2.63M) x 320 = 841.60M of memory is required在核心滴滴涕的大小（2.63M）× 320 = 841.60M内存是必需的

Conclusion结论
After you evaluate the two constraints on deduplication, the deduplication ratio and the memory requirements, you can make a decision about whether to implement deduplication and what the likely savings will be.评估重复数据删除，重复数据删除率和内存要求的两个约束后，你可以决定是否实施重复数据删除，并可能将节省。

For More Information欲了解更多信息
Here are some additional resources:这里有一些额外的资源：

 Download Oracle Solaris 11下载的Oracle Solaris 11

 Access Oracle Solaris 11 product documentation访问的Oracle Solaris 11产品文档

 Access all Oracle Solaris 11 how-to guides访问所有的Oracle Solaris 11操作指南

 Learn more with Oracle Solaris 11 training and support了解更多的Oracle Solaris 11培训和支持

励志 故事(7)

、气候类型的判读

[目标定位]   气候类型的判读是高中地理知识中的重点、难点，更是高考的必考点。许多综合性问题的突破点立足于气候类型的判读，根据图文信息准确判读气候类型是必须掌握的一项基本技能。气候类型的判读不仅要掌握一定的理论知识和基本方法，更要熟悉各种气候类型资料图的命题形式和解读思路。气候类型考查的图式多种多
qiduwx.com提示您，本章还有下一页点击继续阅读！