[lxc-devel] [PATCH] snapshots: move snapshot directory (v5)

Sun Jun 1 21:31:37 UTC 2014

On Sat, May 31, 2014 at 8:11 PM, S.Çağlar Onur <caglar at 10ur.org> wrote:
> On Fri, May 30, 2014 at 11:54 PM, S.Çağlar Onur <caglar at 10ur.org> wrote:
>> On Fri, May 30, 2014 at 6:41 PM, Serge Hallyn <serge.hallyn at ubuntu.com> wrote:
>>> Quoting Serge Hallyn (serge.hallyn at ubuntu.com):
>>>> Quoting S.Çağlar Onur (caglar at 10ur.org):
>>>> > On Wed, May 28, 2014 at 8:32 PM, S.Çağlar Onur <caglar at 10ur.org> wrote:
>>>> > > Hi Serge,
>>>> > >
>>>> > > On Tue, May 27, 2014 at 5:24 PM, Serge Hallyn <serge.hallyn at ubuntu.com> wrote:
>>>> > >> Originally we kept snapshots under /var/lib/lxcsnaps.  If a
>>>> > >> separate btrfs is mounted at /var/lib/lxc, then we can't
>>>> > >> make btrfs snapshots under /var/lib/lxcsnaps.
>>>> > >>
>>>> > >> This patch moves the default directory to /var/lib/lxc/c/snaps.
>>>> > >> If /var/lib/lxcsnaps already exists, then we continue to use that.
>>>> > >>
>>>> > >> add c->destroy_with_snapshots() and c->snapshot_destroy_all()
>>>> > >> API methods.  c->snashot_destroy_all() can be triggered from
>>>> > >> lxc-snapshot using '-d ALL'.  There is no command to call
>>>> > >> c->destroy_with_snapshots(c) as of yet.
>>>> > >>
>>>> > >> lxclock: use ".$lxcname" for container lock files
>>>> > >> that way we can use /run/lock/lxc/$lxcpath/$lxcname/snaps as a
>>>> > >> directory when locking snapshots without having to worry about
>>>> > >> /run/lock//lxc/$lxcpath/$lxcname being a file.
>>>> > >>
>>>> > >> destroy: split off a container_destroy
>>>> > >> container_destroy() doesn't check for snapshots, so snapshot_rename can
>>>> > >> use it.  api_destroy() now does check for snapshots (previously it only
>>>> > >> checked for fs - i.e. overlayfs/aufs - snapshots).
>>>> > >>
>>>> > >> Add destroy to the manpage, as it was previously undocumented.
>>>> > >>
>>>> > >> Update snapshot testcase accordingly.
>>>> > >>
>>>> > >> Signed-off-by: Serge Hallyn <serge.hallyn at ubuntu.com>
>>>> > >
>>>> > > This version is not cleanly getting applied on top of current master
>>>> > > so I ended up modifying the patch locally. I might have introduced a
>>>> > > problem or two while doing that cause my tests started to fail with
>>>> > > this. Unfortunately I haven't been able to find some time to debug it
>>>> > > further. Will try again and catch you on irc tomorrow.
>>>> >
>>>> > So I found why my tests are failing and my first reaction was blaming
>>>> > the Go bindings but then I realized that python bindings are also not
>>>> > working. Somehow this patch is causing create to fail and I'm not
>>>> > seeing how. Please see below, same thing happens with Go (a file named
>>>> > as template argument appears in the directory but nothing else
>>>> > happens) but lxc-create works just fine.
>>>> >
>>>> > [caglar at qop:~/t] pwd
>>>> > /home/caglar/t
>>>> > [caglar at qop:~/t] sudo lxc-ls
>>>> > [caglar at qop:~/t] ls
>>>> > [caglar at qop:~/t] sudo python3
>>>> > Python 3.4.0 (default, Apr 11 2014, 13:05:11)
>>>> > [GCC 4.8.2] on linux
>>>> > Type "help", "copyright", "credits" or "license" for more information.
>>>> > >>> import lxc
>>>> > >>> c = lxc.Container("r")
>>>> > >>> c.create("ubuntu")
>>>> > True
>>>> > >>>
>>>> > [caglar at qop:~/t] cat ubuntu
>>>> > lxc.network.type = veth
>>>> > lxc.network.flags = up
>>>> > lxc.network.link = lxcbr0
>>>> > lxc.network.hwaddr = 00:16:3e:e6:0b:a0
>>>>
>>>> Hey,
>>>>
>>>> ok so I tried to reproduce this just now and couldn't.  Which tree did
>>>> you apply this to?  Can you maybe push the result as a git tree?  Before
>>>
>>> Or, the whole tree I originally was using is at git://github.com/hallyn #snaps5
>>
>> I was testing this patch on top of current master (head is at
>> c83462d56d). I have limited connectivity right now but I'll push it to
>> a branch tomorrow and will let you know.
>
> I pushed it to a branch called serge at https://github.com/caglar10ur/lxc
>
> As a sanity check, I started with current master which was working
> fine then installed the branch and problem appeared again

Serge, I believe you can ignore this problem for now. Looks like it is
not an issue if you do a fresh compilation. To reproduce, you need to
start with compiling master (and then installing it on to your system)
and then applying your patch on top of that and do a make followed by
make install.

My tests started to pass again expect one where I restore a snapshot
as a new container. I'll debug more to see whether it's related with
LXC or Go bindings cause as long as I see lxc-snapshot command works
fine for that case.

> [caglar at qop:~] mkdir t
> [caglar at qop:~] cd t
> /home/caglar/t
> [caglar at qop:~/t] sudo lxc-ls
> [caglar at qop:~/t] sudo python3
> Python 3.4.0 (default, Apr 11 2014, 13:05:11)
> [GCC 4.8.2] on linux
> Type "help", "copyright", "credits" or "license" for more information.
>>>> import lxc
>>>> c = lxc.Container("t")
>>>> c.create("ubuntu")
> Checking cache download in /var/cache/lxc/trusty/rootfs-amd64 ...
> Copy /var/cache/lxc/trusty/rootfs-amd64 to /var/lib/lxc/t/rootfs ...
> Copying rootfs to /var/lib/lxc/t/rootfs ...
> Generating locales...
>   en_US.UTF-8... up-to-date
> Generation complete.
> Creating SSH2 RSA key; this may take some time ...
> Creating SSH2 DSA key; this may take some time ...
> Creating SSH2 ECDSA key; this may take some time ...
> Creating SSH2 ED25519 key; this may take some time ...
> update-rc.d: warning: default stop runlevel arguments (0 1 6) do not
> match ssh Default-Stop values (none)
> invoke-rc.d: policy-rc.d denied execution of start.
>
> Current default time zone: 'America/New_York'
> Local time is now:      Sat May 31 20:08:44 EDT 2014.
> Universal Time is now:  Sun Jun  1 00:08:44 UTC 2014.
>
>
> ##
> # The default user is 'ubuntu' with password 'ubuntu'!
> # Use the 'sudo' command to run tasks as root in the container.
> ##
>
> True
>>>>
> [caglar at qop:~/t] sudo lxc-destroy -n t
>
> [caglar at qop:~/t] cd /home/caglar/Projects/lxc
> [caglar at qop:~/Projects/lxc(serge)] sudo make install
> [...]
> [caglar at qop:~/Projects/lxc(serge)] cd /home/caglar/t
> [caglar at qop:~/t]
>
> [caglar at qop:~/t] sudo lxc-destroy -n t
> [caglar at qop:~/t] sudo python3
> Python 3.4.0 (default, Apr 11 2014, 13:05:11)
> [GCC 4.8.2] on linux
> Type "help", "copyright", "credits" or "license" for more information.
>>>> import lxc
>>>> c = lxc.Container("t")
>>>> c.create("ubuntu")
> True
>>>>
> [caglar at qop:~/t] ls
> ubuntu
> [caglar at qop:~/t] cat ubuntu
> lxc.network.type = veth
> lxc.network.flags = up
> lxc.network.link = lxcbr0
> lxc.network.hwaddr = 00:16:3e:35:4e:31
> [caglar at qop:~/t]
>
>
>
>>>> I was just building from git and had no problems.  This time I
>>>> pushed against https://launchpad.net/~ubuntu-lxc/+archive/daily/+files/lxc_1.0.3%2Bmaster%7E20140525-1523-0ubuntu1%7Etrusty.dsc
>>>> (which required some twiddling as the ppa appears to be out of date),
>>>> but still creation through the api is working fine for me.  Tried
>>>> both busybox and ubuntu templates.
>>>>
>>>> Is it possible that you installed in a way that there are no available
>>>> templates (or they are in the wrong place)?  Still doesn't explain
>>>> why 'ubuntu' would show up in your current path...
>>> _______________________________________________
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>>> http://lists.linuxcontainers.org/listinfo/lxc-devel
>>
>>
>>
>> --
>> S.Çağlar Onur <caglar at 10ur.org>
>
>
>
> --
> S.Çağlar Onur <caglar at 10ur.org>

-- 
S.Çağlar Onur <caglar at 10ur.org>