实用技巧: 光纤通道交换环境的最佳策略
欢迎进入网络技术社区论坛,与200万技术人员互动交流 >>进入 将SAN的设置信息备份到硬盘中,而不是SAN中。 SAN一般不会发生错误,但是一旦发生错误,问题就严重了。如果将SAN文档备份到与网络驱动相连的服务器中,而驱动又在SAN中,那么存储团队就会丢失恢复
欢迎进入网络技术社区论坛,与200万技术人员互动交流 >>进入
将SAN的设置信息备份到硬盘中,而不是SAN中。
SAN一般不会发生错误,但是一旦发生错误,问题就严重了。如果将SAN文档备份到与网络驱动相连的服务器中,而驱动又在SAN中,那么存储团队就会丢失恢复系统所需的信息。
Iacono说:“我可以告诉你,《财富》50强公司也这么做,真是令人吃惊。”
许多公司甚至没有更新SAN文档。他们通常从Excel线程开始工作,出发点很好,但是几乎从不更新,因为面临着更加紧迫的任务。
“如果让他们检查故障,他们甚至不知道哪些信息与哪些端口相连。” Iacono说,“每个人都会涉及此类文档,但是50%到70%的文档都没有及时更新。”
管理:人事方面
雇佣专业的存储团队和完善的变更管理程序。
SAN出现问题,通常是由于人为错误。严格的变更管理策略能够降低错误发生率。同理,专业的存储团队能积极管理系统,减少错误率。
服务器管理员需要与存储团队交流、协调需求,因为存储是由存储团队设计完成的。一位存储专家记下流程步骤和设置说明,包括存储阵列和交换机的任务。理想情况下,另一位存储专家会审核变更设计,从而保证质量。
Gartner的Passmore认为:“实际上,遵循这些规则的公司多年来一直在SAN领域取得成功。”
为访问SAN的每位管理员和第三方咨询师设置独立的用户帐户和密码。
Iacono说,很多情况下,管理员在调整新交换机的参数后没有转告同事。他发现同一台交换机拥有不同的配置,询问发生了什么情况,通常会听到这种回答“Joe是这么做的,而Steve是那么做的”。
Iacono认为:“一旦明确了职能,这些问题就不复存在。我们希望能够审计所有的过程。”
IT团队不仅能够明确问题来源,而且当SAN管理人员离开公司时,不必重置通用密码。
安全
完成LUN掩码和绑定的同时创建区域。
为新服务器创建存储时,可以利用工具建立存储卷,分配地址或SCSI LUN。如果某些实体不具有LUN,LUN掩码就会将LUN隐藏;LUN绑定只是将LUN附属到服务器中HBA的全局ID中。
完成LUN掩码和绑定的同时,存储专家应该深入交换机,创建区域,而且只允许专门的适配器与特定的存储端口实现通信。
“实际上,交换机通过分区可以强化LUN的掩码和绑定。” Passmore说,“进一步而言,可以设计与服务器通信的端口交换机,从而检查全局ID,在存储阵列中强化LUN的掩码和绑定。”
使用安全外壳(SSH)协议访问SAN。
如果管理员使用Telnet协议登录SAN交换机,密码其实没有受到保护,可能会面临拦截的文献。SSH能提供安全通道。
“采用SSH,一切都受到保护。” Iacono说,“如果你管理的是Windows或Unix环境,这就是一项基本标准,但是处于某些原因,没有人对SAN环境使用SSH。”
虚拟服务器
保证服务器内外流入交换机和指定目标的网络带宽足以适应环境。
如果服务器没有得到充分利用,但又运行了虚拟机中多个应用程序的工作负荷,那么网络带宽的需求就会逐步扩大。用户在设计SAN时需谨记这一点。
“去年,典型的x86服务器经常需要处理每秒一千多兆的吞吐量。”Staimer指出,“当前的x86服务器一般都属于四核,如果应用程序允许的话,很容易就能达到10 GB。如果你同时运行20个程序,就会达到10 GB。而以前的服务器之所以没有达到10 GB,是因为一个程序无法完成。”
保证拥有虚拟机的物理服务器位于同一区域。
管理员可以利用虚拟服务器技术在无需停机的情况下,将应用程序从一台物理服务器转移到另一台物理服务器,但是这些物理服务器需要位于同一光纤通道区域,才能访问存储。
Staimer说:“应用程序无法找到存储,为什么呢?因为程序崩溃了!”
利用支持N_Port ID虚拟化(NPIV)的交换机和HBA。
如果一台物理服务器中运行了五台虚拟机,NPIV就会允许每台虚拟机各自获得一个独特的HBA标识符,具有NPIV功能的交换机能够识别这些独特的ID。这就意味着每台虚拟机都能访问各自的LUN。
如果设备不具备NPIV功能,物理服务器就只能得到一个端口ID。
新型交换机和HBA都支持NPIV,但是使用遗留硬件的人员可能需要检查供应商如何更新固件。NPIV处理刀片服务器的方式与其处理虚拟服务器的方式非常相似。
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