The jtreg test java/io/File/GetXSpace.java generates failures on Linux / AIX (on some other platforms it is currently exluded).
So it might be a good idea to exclude it too on AIX/Linux.
 
One stderr example from Linux :
 
FAILED: '/net/mywork': 14059035885568 != 14059035230208
FAILED: '/net/mywork': 14059035885568 != 14059034902528
Exception in thread "main" java.lang.RuntimeException: 416 tests: 2 failure(s), first
        at GetXSpace.main(GetXSpace.java:383)
Caused by: java.lang.RuntimeException: '/net/mywork': 14059035885568 != 14059035230208
        at GetXSpace.setFirst(GetXSpace.java:99)
        at GetXSpace.fail(GetXSpace.java:84)
        at GetXSpace.compare(GetXSpace.java:224)
        at GetXSpace.testDF(GetXSpace.java:367)
        at GetXSpace.main(GetXSpace.java:379)

One idea was that nfs mount should be ignored by the test, because they might change while the test is working.