Xen project Mailing List

On Tue, Nov 22, 2011 at 7:29 AM, Florian Heigl <florian.heigl@xxxxxxxxx> wrote:

2011/11/22 Michael A. Collins <mike.a.collins@xxxxxxxxxxx>:

> On 22.11.2011 01:56, Shriram Rajagopalan wrote:
>
>> eh? I dont think so. with drbd based backend for xen VMs (with or without
>> remus),
>> you just use the drbd:<resourceName> syntax (much like phy:...).

> The drbd:<resource> syntax works for xm, but not for xl. I'll have to work

That's what I ended up with, too

>> With all that said and done, I’m currently running drbd 8.3.11 since
>> that’s the version of the kernel module included with Linux 3.1, but
>> I’m just using Xen’s phy handler for the disk section of my VM’s
>> cfg file.

wasn't there something in remus that demands you have a drbd: device
if you're not using blktap?

>> I see that there is a nice howto for debian on remusha.wikidot.com
>> [5], but again it uses a 2.6.32 kernel from Jeremy’s git repo, which
>> has the tap kernel module. I again assert that currently there is
>> very little out there that would help to get someone started using
>> remus with drbd in the linux 3.1.x world. I run remus at work, but
>> it’s using shared storage and have no need to use it with drbd, but
>> at home I don’t really want to set that up, so I thought drbd would
>> be a nice start.
>>
>>
>>
>> I’ve started diffing the 8.3.9 branch of drbd with your changes for
>> remus and will see how hard it is to get that in the 8.3.11 version
>>
>>>
>>> Is the remusified drbd (8.3.9) not compiling under the 3.1.x kernel
>>> anymore or are you interested in
>>> the latest version of DRBD + the remus stuff ?
>>>
>>>
>>> shriram
>
> I am interested in running the latest drbd changes with remus. But I am
> interested in getting this to work through the xl interface more than
> anything.

Well, there is no xl support for remus as of yet. The main barrier being
the disk specification issue (mentioned below) and libnetlink interface to manipulate
the VM's network interface. Am working on that.

Currently there's no alternate reality available in which one can run Remus?
blktap - not really there (and it would have other nice features)
dr:bd - doesn't play with xl

its drbd btw :).
can u just start a domain with drbd backend disk? (no remus) or anything.
I mean using the drbd:<resourceName> syntax (as described in the DRBD website)
or using the "script=drbd,backendtype=phy,format=raw,target=resourceName" syntax in xl.

I have tried and it doesnt work. xl defaults (hardcoded?) to tap backend.
doing a grep in the tools/libxl directory, I can see that there is no implementation
for invoking the script supplied as part of disk spec.

if (disk->script) {
        LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "External block scripts"
                   " not yet supported, sorry");
        rc = ERROR_INVAL;
        goto out_free;
    }

xm - not supposed to use that any more
older distros - will not take remus patches i guess
older howtos - broken since Remus is already part of Xen by now

(And I don't think it will get better by pointing at a workaround else
if one thing that should work isn't working.
Instead, soon, it will no longer work at all)

Re: [Xen-users] [Xen-devel] BLKTAP