转轴到底是什么呢？

Question

Current Disk Queue Length： 应维持在不超过构成物理磁盘的转轴数量的 1.5 倍到 2 倍

大多数物理磁盘只有一个转轴，但独立磁盘冗余阵列 (RAID) 可能有多个转轴。

是组成RAID的物理磁盘的数量？

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If you haven't all the things you want,be grateful for the things you don't have that you didn't want.

Answer 1

是的。你看的什么地方的翻译？Windows里面提到的是轴。你可以理解为磁盘的数量。

Perfmon里面的描述：

Current Disk Queue Length 是在收集性能数据时磁盘上当前的请求数量。它还包括在收集时处于服务的请求。这是瞬间的快照，不是时间间隔的平均值。多轴磁盘设备能有一次处于运行状态的多重请求，但是其他同期请求正在等待服务。此计数器会反映暂时的高或低的队列长度，但是如果磁盘驱动器被迫持续运行，它有可能一直处于高的状态。请求的延迟与此队列的长度减去磁盘的轴数成正比。为了提高性能，此差应该平均小于二。

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想不想时已是想，不如不想都不想。

Answer 2

是的。你看的什么地方的翻译？Windows里面提到的是轴。你可以理解为磁盘的数量。

Perfmon里面的描述：

Current Disk Queue Length 是在收集性能数据时磁盘上当前的请求数量。它还包括在收集时处于服务的请求。这是瞬间的快照，不是时间间隔的平均值。多轴磁盘设备能有一次处于运行状态的多重请求，但是其他同期请求正在等待服务。此计数器会反映暂时的高或低的队列长度，但是如果磁盘驱动器被迫持续运行，它有可能一直处于高的状态。请求的延迟与此队列的长度减去磁盘的轴数成正比。为了提高性能，此差应该平均小于二。

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想不想时已是想，不如不想都不想。

也就是说Current Disk Queue Length的正常范围是小于转轴数量-2？
那么% Disk Time呢？假如是RAID的话，正常范围是？

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If you haven't all the things you want,be grateful for the things you don't have that you didn't want.

Answer 3

Depends on disk config, should check with queue length together.

Answer 4

Depends on disk config, should check with queue length together.

假如4块盘做的RAID5 那么Disk Queue Length的合理范围是多少呢？

另外 假如是4块盘做的RAID10 那么Disk Queue Length的合理范围是否和之前一致？

换句话说，不管做的什么RAID，DISK Queue Length只是根据磁盘数量计算而不管什么RAID吗？

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If you haven't all the things you want,be grateful for the things you don't have that you didn't want.

Answer 5

There's no absolute reasonable number here although MS has some number in their white papers. We have servers for BI with heavy etl processes, we are not worry about disk queue length on them as long as etl can finish in scheduled time. But for other oltp server that requires very quick response time, we'll do whatever to make every components run as faster as possible.

Answer 6

There's no absolute reasonable number here although MS has some number in their white papers. We have servers for BI with heavy etl processes, we are not worry about disk queue length on them as long as etl can finish in scheduled time. But for other oltp server that requires very quick response time, we'll do whatever to make every components run as faster as possible.

是的 我们这边就是简单的OLTP的环境，但是有些时候Disk Queue Length比较大，所以我想知道到底这个值的合理范围是多少

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If you haven't all the things you want,be grateful for the things you don't have that you didn't want.

Answer 7

If it affects your apps, you should work on it even the number is in 'reasonable' range. For MS recommendation, you can check performance tuning article in technet.