Use SSHFS on XenServer 6.1

Solution 1:

Although this is an old question, I have just figured this one out myself.

First.. what DOES NOT WORK (All tested on XenServer 6.5):

xe-import filename=/dev/stdin does not work.. at all. It does not matter whether you do:

# simple local import on xenhost
xe vm-import filename=/dev/stdin < myexport.xva

# try it the other way, with cat, still won't work:    
cat myexport.xva | xe vm-import filename=/dev/stdin

# and no, dd instead of cat in the above does not make it better

# nor can you pull the file from elsewhere via ssh:
ssh user@backupserver "cat myexport.xva" |  xe vm-import filename=/dev/stdin

# nor the other way, pushing from elsewhere to your xenserver
ssh root@xenhost "xe vm-import filename=/dev/stdin" < myexport.xva

# named pipes don't work either, even locally:
mkfifo mypipe
cat myexport.xva > ./mypipe &
xe vm-import filename=./mypipe

So, what I have found is that there is no way to import from a stream, it has to be a real filesystem of some sort. Apparently this used to work, but it doesn't now. My guess is that xenserver wants to seek.

(If anyone can spot a flaw in my attempts and prove me wrong, I'd be very grateful).

So, yes, my conclusion is that you must use a remote filesystem, and we know that NFS works for this, because we've used it.. but decided on sshfs for simplicity. Here is how I installed sshfs on XenServer 6.5:

# fuse-fs and fuse-libs are in existing repos, so..
yum --enablerepo=base --disablerepo=citrix install fuse-fs
# for some reason yum wanted to install i386 fuse-libs which fails
# because of a dependency on i386 glibc.. nevermind all that, tell it
# directly that we want x86_64 and it will work:
yum --enablerepo=base --disablerepo=citrix install fuse-libs.x86_64

# fuse-sshfs is in the epel repo, which we need to add
yum --disablerepo=citrix --enablerepo=extras install epel-release
# now install fuse-sshfs
yum --disablerepo=citrix --enablerepo=extras install fuse-sshfs

# The above leaves epel-release enabled, which should be no problem but
# nevertheless I disabled it since I don't need it anymore:
#   Use vim to edit /etc/yum.repos.d/epel.repo
#   Where it says `enabled=1` change to `enabled=0`
vim /etc/yum.repos.d/epel.repo

Ok now to restore from an export on another machine:

# make mount point
mkdir backups

# mount location of your backups onto mount point
sshfs [email protected]:/path/to/backups backups

# import as usual
xe vm-import filename=backups/myexport.xva

# unmount the remote filesystem, if you don't need it anymore
umount backups

# IT WORKS

Oh, and I should add.. I tried installing the xenxerver tools on our backup server.. it does not work either. Sure, you can execute commands and it all looks great. But filename=/dev/stdin still does not work, NOR DOES filename=/path/to/myexport.xva. It just hangs or starts importing then fails in weird ways.

So that's importing.. but what about exporting? Using the xenserver tools remotely installed:

xe vm-export uuid=the-vm-uuid filename= -s xenhost.my.domain -u root -pwf password_file

This DOES export to stdout. But it's a bit unclear as to whether those exports will always import successfully. I experienced a couple of failures and some successes. SO decided against using remote tools at all.. but do it via ssh instead:

ssh [email protected] "vm-export uuid=the-vm-uuid filename=" > myexport.xva

IT WORKS!

The upshot of this is that, with our backup system (Bareos) it is possible to do a backup via ssh directly into the backup software, without having to do an export to a temporary file first. But to do the restore, it is necessary to restore the xva to a temporary storage first, then mount on the xenhost with sshfs, then vm-import. I am sad that we can't stream both ways.. hopefully this will be fixed in xe some time.

Hope this helps some people.. it took a good amount of trial and error to test all the possibilities :)

Solution 2:

If you want to have a way to import your xva-backups into XenServer, you can simply install the xe guest utilities onto your backup server. They are included in the xentools iso (linux folder). then you can use " xe -s serverip -u root -pw password vm-import..." to import your backups (or even export them).

Btw: Connection is secured via SSL.