Hello,
on my all-in-one installation @home I had 3.5.0 with F20.
Today I updated to 3.5.1.

it seems it modified /etc/multipath.conf preventing me from using my second disk at all...

My system has internal ssd disk (sda) for OS and one local storage domain and another disk (sdb) with some partitions (on one of them there is also another local storage domain).

At reboot I was put in emergency boot because partitions at sdb disk could not be mounted (they were busy).
it took me some time to understand that the problem was due to sdb gone managed as multipath device and so busy for partitions to be mounted.

Here you can find how multipath became after update and reboot
https://drive.google.com/file/d/0BwoPbcrMv8mvS0FkMnNyMTdVTms/view?usp=sharing

No device-mapper-multipath update in yum.log

Also it seems that after changing it, it was then reverted at boot again (I don't know if the responsible was initrd/dracut or vdsmd) so in the mean time the only thing I could do was to make the file immutable with

chattr +i /etc/multipath.conf

and so I was able to reboot and verify that my partitions on sdb were ok and I was able to mount them (for safe I also ran an fsck against them)

Update ran around 19:20 and finished at 19:34
here the log in gzip format
https://drive.google.com/file/d/0BwoPbcrMv8mvWjJDTXU1YjRWOFk/view?usp=sharing

Reboot was done around 21:10-21:14

Here my /var/log/messages in gzip format, where you can see latest days.
https://drive.google.com/file/d/0BwoPbcrMv8mvMm1ldXljd3hZWnM/view?usp=sharing


Any suggestion appreciated.

Current multipath.conf (where I also commented out the getuid_callout that is not used anymore):

[root@tekkaman setup]# cat /etc/multipath.conf
# RHEV REVISION 1.1

blacklist {
    devnode "^(sda|sdb)[0-9]*"
}

defaults {
    polling_interval        5
    #getuid_callout          "/usr/lib/udev/scsi_id --whitelisted --replace-whitespace --device=/dev/%n"
    no_path_retry           fail
    user_friendly_names     no
    flush_on_last_del       yes
    fast_io_fail_tmo        5
    dev_loss_tmo            30
    max_fds                 4096
}


Gianluca