Many people ask me what vSAN compared to traditional storage, and the advantage is, in fact, this question difficult to answer because everyone's point of concern is not the same, some people are concerned about performance, some people are concerned about the price, some people are concerned about stability, people are concerned about maintainability. I think as a system administrator, should be more concerned about the stability and maintainability.
There are two sets stored in our laboratory, a traditional EMC optical storage, set a vSAN. Optical storage have spent nearly four years, all of the disk slot has been studded, so about two years ago, we started to build their own vSAN environment. From the beginning of hosts 2 to 5 now hosts (yes, 2 ...), the whole vSAN environment has continued to run close to 2 years. So these two years have not upgraded optical storage, also temporarily not to buy in the future of optical storage plan. As a vSAN users and system administrators, I think there is some experience that can be shared.
I remember just join when often need to run the customer site installation and commissioning hosts and storage devices. If you need to install a new optical storage configuration, roughly divided into the following steps:
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Confirm host physical installation, system installation is complete, normal operation
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Physical installation of storage, including shelves, wiring, power initialization.
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Raid manner using the underlying physical storage pool to create a hard disk, for example Raid1 + 0 or Raid5
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Creating Lun in the storage pool in accordance with customer demand
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Configuration Zone fabric switches
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Storage node mapping LUN, and to ensure that the host can correctly recognize the newly added LUN
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Create a host file system (e.g. VMFS Datastore) After identifying the LUN
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Start using (for example: create a new VM is stored on Datastore added)
(Installed after commissioning of optical storage even bigger project - tie line, otherwise the rear of the cabinet is like this ...)
以上是一个简单的添加光纤存储的基本过程，期间需要涉及到不同厂商工程师之间的配合，例如存储工程师、网络工程师、系统管理员和主机工程师。而且更重要的是，所有的VM都是只能按照创建存储池时使用的Raid模式进行储存的。如果需要修改底层的存储池的Raid模式，例如从Raid1改为Raid5，则这个存储池需要删掉新建（不知道现在是不是这个样子了），上面储存的资料也需要事先迁移到其他的存储上或者从备份中恢复，这就是一个比较费力的工作了…
使用vSAN就是完全不同的体验了，安装一套全新的vSAN大概是这个流程：
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确认主机物理安装完毕，系统安装完成，运行正常
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配置vSAN vmk，确保vSAN vmk可以ping通
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启用vSAN功能。
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创建磁盘组
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创建VM并且选择需要测存储策略
是的，就是这么简单。如果进行扩容的话就更加简单了，直接插入新的硬盘，然后加入新的磁盘组或者创建新的磁盘组就可以了...两周以前我刚刚扩容了12T新的空间到vSAN里，从插入磁盘到添加完磁盘组整个过程不超过10分钟。
那么我们看出vSAN和传统存储的区别了么？
首先工作量很小，基本上在网络交换机配置好的情况下只需要涉及主机工程师和系统管理员。其次不用添加额外的存储设备，所以节省了机柜空间，供电和空调的花费，设备之间的连线也更加简单。最重要的是，用户可以根据实际需求灵活的修改VM的存储策略，例如：一个重要的VM可以选择多副本的存储策略，一个不重要的VM可以选择单副本的存储策略，而VM可以在线的更换存储策略。
（vSAN 主机背后的连线非常简单）
因此，对于一个运维人员来说，vSAN的优势包括下面四点：
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更快速的部署
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更简单的配置方式
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更优秀并且稳定的性能
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更简单灵活的维护方式
希望这些优点可以帮助运维人员节省更多的精力，有更多的时间去享受生活～～
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刚刚回到北京一天就已经开始想念成都的小吃了
