cn website: add Chinese homepage

Change-Id: I54c50ab0e0595b3b3ea517fcac3539fb22d39125
Signed-off-by: Wenyun Xu <[email protected]>
Reviewed-on: https://review.gerrithub.io/424165
Reviewed-by: GangCao <[email protected]>
Reviewed-by: Jim Harris <[email protected]>
Tested-by: SPDK Automated Test System <[email protected]>

cn/index.md

@@ -1,39 +1,22 @@
 ---
 layout: index
-title: Storage Performance Development Kit
+title: SPDK中文网站
 lang: cn
 ---
+<style>p{ text-indent: 2em; }</style>
+Storage Performance Development Kit (SPDK)提供了一组用于编写高性能、可伸缩、用户态存储应用程序的工具和库。它通过使用一些关键技术来实现高性能:
 
-The Storage Performance Development Kit (SPDK) provides a set of tools and
-libraries for writing high performance, scalable, user-mode storage
-applications. It achieves high performance through the use of a number of key
-techniques:
+* 将所有必需的驱动程序移至用户空间，这样就避免了系统调用，并允许从应用程序中进行零拷贝访问；
+* 轮询硬件任务的完成而不是依靠中断，这会降低总延迟和延迟抖动；
+* 避免在I/O路径中出现锁, 而是依赖消息传递。
 
-* Moving all of the necessary drivers into userspace, which avoids syscalls
-  and enables zero-copy access from the application.
-* Polling hardware for completions instead of relying on interrupts, which
-  lowers both total latency and latency variance.
-* Avoiding all locks in the I/O path, instead relying on message passing.
+SPDK的基础是用户态、轮询、异步、无锁
+[NVMe](http://www.nvmexpress.org) 驱动。这提供了从用户空间应用程序直接访问SSD的零拷贝、高度并行的访问。驱动程序被编写为带有一个公共头文件的C语言库。
 
-The bedrock of SPDK is a user space, polled-mode, asynchronous, lockless
-[NVMe](http://www.nvmexpress.org) driver. This provides zero-copy, highly
-parallel access directly to an SSD from a user space application. The driver is
-written as a C library with a single public header.
+SPDK进一步提供了一个完整的块堆栈，作为一个用户空间库，它执行许多与操作系统中的块堆栈相同的操作。这包括统一不同存储设备之间的接口、通过队列来处理内存不足或I/O挂起等情况以及逻辑卷管理。
 
-SPDK further provides a full block stack as a user space library that performs
-many of the same operations as a block stack in an operating system. This
-includes unifying the interface between disparate storage devices, queueing to
-handle conditions such as out of memory or I/O hangs, and logical volume
-management.
-
-Finally, SPDK provides
+最后，SPDK提供
 [NVMe-oF](http://www.nvmexpress.org/nvm-express-over-fabrics-specification-released),
-[iSCSI](https://en.wikipedia.org/wiki/ISCSI), and
-[vhost](http://blog.vmsplice.net/2011/09/qemu-internals-vhost-architecture.html)
-servers built on top of these components that are capable of serving disks over
-the network or to other processes. The standard Linux kernel initiators for
-NVMe-oF and iSCSI interoperate with these targets, as well as QEMU with vhost.
-These servers can be up to an order of magnitude more CPU efficient than other
-implementations. These targets can be used as examples of how to implement a
-high performance storage target, or used as the basis for production
-deployments.
+[iSCSI](https://en.wikipedia.org/wiki/ISCSI), 和
+[vhost](http://blog.vmsplice.net/2011/09/qemu-internals-vhost-architecture.html)。
+在这些组件之上构建的服务器,能够通过网络或其他进程为磁盘提供服务。NVMe和iSCSI的标准Linux内核启动器与这些target交互, 以及与QEMU和虚拟主机进行交互。与其他实现相比，这些服务器的CPU效率可以提高一个数量级。这些target可以用作实现高性能存储目标的范例，也可以用作生产部署的基础。