Run times for the format utility

These tests were performed to determine how long the formatting of different file systems takes.

Formatting a file system is a fast and easy task, but how long does the formatting of a 1.6 TB file system actually take? Usually, there is no time limitation the first time this task is performed. However, the format time needed in a disaster recover case may be critical. This test case was used to find an average format time.

We used the UNIX time command and sysstat to measure the format time.

Figure 1 and Figure 2 show the total run time to format the file system. The lower values were the better times. The bars in the charts are split to also show the CPU utilization. Non-appearing colors have a value of zero.

Figure 2 is the detailed view of the ReiserFS3 and XFS file systems. These file systems are much faster than the EXT2 and EXT3 file systems so the overall chart does not show the details of the CPU utilization.

Observations

EXT2 and EXT3 are writing the metadata all over the file system on the disk, which takes a little extra time. However, both are still done in less than two minutes. All other file systems are writing only some information at the beginning, which takes between one and four seconds. There is almost no “nice” or “user” CPU consumption.

Conclusion

ReiserFS and XFS are very fast when formatting the disk. The EXT2 and EXT3 are writing some data over the whole disk, which takes a little more time. However, the format times are also low enough that they might be negligible.