[Xen-users] Re: live migration, loopback devices & NFS.

Miguel Gómez
Wed, 13 Jul 2005 16:15:57 -0000

Ok, now I think that it doesn''t has to do with Xen. It has to do with
NFS. I think that the problem is that I am using NFSv2, that can only
handle files smaller than 2Gb. So I will have to use NFSv3.

Take a look at this post:
http://lists.freebsd.org/pipermail/freebsd-questions/2004-June/048294.html

In the nfs client I type:


XENmaster:/# nfsstat
Client rpc stats:
calls      retrans    authrefrsh
17         0          0
Client nfs v2:
null       getattr    setattr    root       lookup     readlink
0       0% 7      41% 0       0% 0       0% 4      23% 0       0%
read       wrcache    write      create     remove     rename
0       0% 0       0% 0       0% 0       0% 0       0% 0       0%
link       symlink    mkdir      rmdir      readdir    fsstat
0       0% 0       0% 0       0% 0       0% 3      17% 3      17%

Client nfs v3:
null       getattr    setattr    lookup     access     readlink
0       0% 0       0% 0       0% 0       0% 0       0% 0       0%
read       write      create     mkdir      symlink    mknod
0       0% 0       0% 0       0% 0       0% 0       0% 0       0%
remove     rmdir      rename     link       readdir    readdirplus
0       0% 0       0% 0       0% 0       0% 0       0% 0       0%
fsstat     fsinfo     pathconf   commit
0       0% 0       0% 0       0% 0       0%


All the traffic is NFSv2. Do you know how can I use NFSv3? I added
this to my /etc/fstab ''s nfs line option:
soft,noauto,nolock,rsize=1024,wsize=1024,intr,retry=10,nfsvers=3

But it doesn''t works, it tells me that I can only use nfsvers=1 or
nfsvers=2.

Thank you!!!!!
Regards,

               Miguel.


















On 7/12/05, Miguel Gómez <elmiguelonmakinon@gmail.com>
wrote:
> Hello people,
> I am trying to do is a live migration between two hosts in my subnet.
> One of them (XENmaster) has NFS service with this line in
> /etc/exports:
>
> /xen    192.168.50.0/255.255.255.0(rw,sync,no_root_squash)
>
> In the other machine (XENslave) I mount that directory with this line:
>
> mount -t nfs XENmaster:/xen    /xen
>
> So in both machines I see the same in /xen directory. In that
> directory I have the loop back devices:
>
> XENmaster:/xen# ls -l
> total 286664
> -rw-r--r--  1 root root 2139119616 2005-07-12 17:56 vmDebian2
> -rw-r--r--  1 root root  268436480 2005-06-30 18:31 vmDebian2Swap
>
>
> XENslave:/xen# ls -l
> total 286664
> -rw-r--r--  1 root root 2139119616 2005-07-12 17:56 vmDebian2
> -rw-r--r--  1 root root  268436480 2005-06-30 18:31 vmDebian2Swap
>
> If I try to create a virtual machine in XENslave (The machine that is
> NOT running NFS), I get that VM starts normally but when it tries to
> check the filesystem it finds a problem:
>
> IP-Config: Complete:
>       device=eth0, addr=192.168.50.213, mask=255.255.255.0,
gw=255.255.255.255,
>      host=192.168.50.213, domain=, nis-domain=(none),
>      bootserver=1.2.3.4, rootserver=1.2.3.4, rootpath> EXT3-fs warning:
mounting fs with errors, running e2fsck is recommended
> kjournald starting.  Commit interval 5 seconds
> EXT3 FS on hda1, internal journal
> EXT3-fs: mounted filesystem with ordered data mode.
> VFS: Mounted root (ext3 filesystem).
> Freeing unused kernel memory: 112k freed
> INIT: version 2.86 booting
> Activating swap.
> Checking root file system...
> fsck 1.37 (21-Mar-2005)
> /dev/shm/root: The filesystem size (according to the superblock) is
> 524288 blocks
> The physical size of the device is 522246 blocks
> Either the superblock or the partition table is likely to be corrupt!
>
>
> /dev/shm/root: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.
>         (i.e., without -a or -p options)
>
> fsck failed.  Please repair manually and reboot.  Please note
> that the root file system is currently mounted read-only.  To
> remount it read-write:
>
>    # mount -n -o remount,rw /
>
> CONTROL-D will exit from this shell and REBOOT the system.
>
> Press enter for maintenance
> (or type Control-D to continue):
>
>
> It seems that something is wrong with the filesystem block size:
>
> /dev/shm/root: The filesystem size (according to the superblock) is
> 524288 blocks
> The physical size of the device is 522246 blocks
> Either the superblock or the partition table is likely to be corrupt!
>
> But I don''t really know how to resolve this. It seems that
there''s a
> problem with NFS and loopback devices, but how do I do this without
> loopback devices? I can create VMs with LVM but, how do I share them?
> What do you do? Has anybody there used live migration? How did you get
> it?
>
> Thank you for your  help.
>  MIguel.
>