File system performance

test procedure

Testing filesystem performance read/write numbers of files into overloaded directory with up to 7 million files.

• start with empty directory
• writing test uses kent source library functions to obtain a unique filename in

 the directory

/dev/shm/ tmpfs in memory filesystem

The null model test. This is the RAM memory filesystem '/dev/shm/'. Performance remains constant despite numbers of files in the directory.

xfs filesystem

Writing performance declines rapidly, reading performance remains constant.

ext4 filesystem

Both read and write performance drop off between one and two million files in the directory.