Description of problem:

On my new, fast machine, the mdadm test very occasionally fails:


PASS: test-inspect-fstab.sh
PASS: test-inspect-fstab-md.sh
PASS: test-list-filesystems.sh
PASS: test-list-md-devices.sh
libguestfs: error: md_detail: mdadm: md device /dev/md125 does not appear to be active.
FAIL: test-mdadm.sh

The error message comes from mdadm's '-D' (detail) subcommand
when the device in question returns ENODEV.

This is the sequence of events (dev == "/dev/md125"):

        int fd = open(dev, O_RDONLY);  # successful
        vers = md_get_version(fd);     # successful, and vers >= 9000
        if (ioctl(fd, GET_ARRAY_INFO, &array)<0) {
                if (errno == ENODEV)
                   ... error message is printed here ...

Version-Release number of selected component (if applicable):

libguestfs 1.17.31
mdadm-3.2.3-7.fc17.x86_64

How reproducible:

infrequently

Steps to Reproduce:
1. make -C tests/md check