Hotband=(min,max): Create a skewed workload over a Limited Seek Range
By default, the whole SD or concatenated SD will be used to generate a random LBA. To limit the lba range for a workload, specify the starting and ending range of the SD: hotband=(40,60) will limit I/O activity starting at 40% into the SD and ending at 60% into the SD. If the max value is larger than 100 but smaller than 200, Vdbench will consider this a wrap across the end of your SD. For instance with hotband=(90,110) , Vdbench will generate an I/O workload using the last 10% and the first 10% of your volume. When the values are greater than 200, the values will be considered given in bytes instead of in percentages; e.g., Hotband=(1g,2g).
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Hotband has a skewed workload across the defined range. The probability (Pb) accessing a block in the range is biased toward lower LBAs It is intended to simulate something similar to database index. This access will allow for systems with a small cache to have a small cache hit. Systems with larger caches, have larger cache hit rates. The cache rate does not increase linearly as system cache size increases. Here is a sample scatter plot of four hotbands and the intensity of access is skewed to lower LBA. The X axis is the storage LBA range, the Y axis is time.
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Hotband=(min,max): 在有限的寻址范围内创建倾斜的工作负载
默认情况下，整个SD或串联SD将用于生成随机LBA。要限制工作负载的LBA范围，请指定SD的起始和结束范围：hotband=(40,60)将限制从SD的40%处开始到SD的60%处结束的I/O活动。如果最大值大于100但小于200，Vdbench将认为这是在您的SD末尾跨越的情况。例如，对于hotband=(90,110)，Vdbench将使用卷的最后10%和第一个10%生成I/O工作负载。当值大于200时，将以字节而不是百分比的方式给出值；例如，Hotband=(1g,2g)。
Hotband在定义的范围内具有倾斜的工作负载。访问该范围内块的概率（Pb）倾向于较低的LBA。它旨在模拟类似于数据库索引的情况。这种访问方式可以使具有小缓存的系统具有较高的缓存命中率。对于具有更大缓存的系统，缓存命中率会更高。随着系统缓存大小的增加，缓存命中率不会线性增加。这里是四个热带的样本散点图，显示访问的强度倾向于较低的LBA。X轴表示存储LBA范围，Y轴表示时间。