Same on centos6 trying to use a bind mount:

Thread-5189::ERROR::2015-08-25 15:22:26,318::hsm::2379::Storage.HSM::(connectStorageServer) Could not connect to storageServer
Traceback (most recent call last):
  File "/usr/share/vdsm/storage/hsm.py", line 2376, in connectStorageServer
    conObj.connect()
  File "/usr/share/vdsm/storage/storageServer.py", line 220, in connect
    self.getMountObj().getRecord().fs_file)
  File "/usr/share/vdsm/storage/mount.py", line 271, in getRecord
    (self.fs_spec, self.fs_file))
OSError: [Errno 2] Mount of `/data/test` at `/rhev/data-center/mnt/_data_test_` does not exist

And the mount gets mounted on the OS:

/data/test on /rhev/data-center/mnt/_data_test_ type none (rw,bind)

Mount options are:
Path: /data/test/
VFS type: loop
Options: bind,rw

Cheers,
Steve

On Tue, Aug 25, 2015 at 3:22 PM, Steve Kilduff <kilduff@gmail.com> wrote:
Hi guys, trying to reply to a previous topic but I am certain I am not doing it correct, regardless, here we go.

moosefs mounting on ovirt.

I am having similar problem to the person in the mail Cannot add Posix Storage. This is an ovirt setup attempt with moosefs. 

Mount options are:
Path:       mfsmount
VFS type: fuse
Mount opt: mfsmaster=mfsmaster,mfsport=9421,mfssubfolder=/ovirt,_netdev

I specified a subfolder which may not exist on your mfs storae.

In my setup, ovirt mounts the actual mfs mount without problem, the mount remains mounted afterwards as ovirt does not seem to unmount it successfully. I think the problem is the mount detection mechanism in python, It is looking for a pattern to match both the source/destination of the mount and failing: I hope this shows what I mean:
vsdm.log output:
OSError: [Errno 2] Mount of `mfsmount` at `/rhev/data-center/mnt/mfsmount` does not exist

centos7 output of mount command:
mfsmaster:9421 on /rhev/data-center/mnt/mfsmount type fuse.mfs (rw,relatime,user_id=0,group_id=0,allow_other)

Source = mfsmount in first error out line, and source = ''mfsmaster:9421' on the OS, and I guess mount.py is trying to pattern match the mount and doesnt compare them correctly and bails out.

I guess normally the source of the mount does not change name, like with the specifics I gave to mount mfs.

I am trying to poke around the python to see if I can simply ignore this check, but my python skills are non existent.

Also, as a workaround, I tried to first mount mfs without ovirt, and then get ovirt to bind mount my /mnt/moosefs how-ever in centos7 bind mount names are strange, I think broken when compared to centos6,  the output of mount in centos7 when bind mounting /mnt/moosefs to /ovirt:
mfsmaster:9421 on /mnt/moosfs
mfsmaster:9421 on /ovirt

where as in centos6 it would be:
mfsmaster:9421 on /mnt/moosfs
/mnt/moosfs on /ovirt

Again, I think the pattern matching of mount.py is what fails during bind mount also. 

I think if bind mounting worked, the user could stick what-ever filesystem they wanted onto the OS, and get ovirt to bind mount it. Then it's the user's problem how to manage their FS.

Best,
Steve Kilduff