Slow filesystem access

It could still be the XFS filesystem in this case. You may have heavy fragmentation issues as well as the slowdown that comes with a nearly-full filesystem. You could benefit from more space in either case.

Please check the XFS filesystem's fragmentation. You can do this with the xfs_db command. If the filesystem is /dev/sdb1, for example, then you command would look like:

xfs_db -r -c frag /dev/sdb1

That will output a fragmentation factor:

actual 66524, ideal 55966, fragmentation factor 15.87%

You can run the online defragmentation utility, xfs_fsr -v, in a screen session to try to rectify this. By default, the command runs for 2 hours or TEN passes on the filesystem. You may have to run it multiple times. Check the fragmentation factor between runs.

Unix filesystems don't like being full. Try growing the slow filesystem. If that's not possible, try defragging it using xfs_fsr