Citrix XenServer 5.5 + drbd for HA

[Ingmar-3]

Hi,

are there news regarding Citrix XenServer 5.5 and drdbd as HA solution?

Florian told me some months ago that so far there is no known solution for this.

Has someone already implemented this? Is there a guide / how-to for this
solution?

Is this solution better or worse than a HA-cluster with Xen-OS and drbd to
eg Debian 5. What would be the advantages and disadvantages of this
solution?

regards
Ingmar

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[Adam Gandelman-2]

Hi Ingmar-

DRBD can be used from within xenserver to replicate storage
repositories.  This is documented in our extended users guide.  You can
also use DRBD to build HA iSCSI/NFS clusters to serve HA SRs to an
entire xenserver pool.  However, HA on the VM level is the job of a
higher level cluster manager and, AFIK, this is either not possible to
do with OCF-based CRMs or nobody has developed it yet.  It is something
I plan on looking into in the coming months.  Citrix offers an
enterprise add-on for this but it does not provide any redundancy on the
storage level, so some other  form of shared storage (more $$) is
required.  If you need HA storage repositories for your xenserver domUs,
DRBD is a relatively easy "drop in" solution.

If you do not need or want the features of XenServer/XenCenter,
heartbeat/pacemaker can monitor OSS Xen domUs in addition to DRBD.
There is an Xen OCF script that is shipped with Pacemaker.

hope that helps
Adam



Beck Ingmar wrote:

> Hi,
>
> are there news regarding Citrix XenServer 5.5 and drdbd as HA solution?
> Florian told me some months ago that so far there is no known solution
> for this.
>
> Has someone already implemented this? Is there a guide / how-to for this
> solution?
>
> Is this solution better or worse than a HA-cluster with Xen-OS and
> drbd to
> eg Debian 5. What would be the advantages and disadvantages of this
> solution?
>
> regards
> Ingmar
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> drbd-user mailing list
> drbd-user@...
> http://lists.linbit.com/mailman/listinfo/drbd-user
>  

--
: Adam Gandelman
: Telephone: [phone] Ex. 203
: LINBIT | Your Way to High Availability
: Sales: 1-877-4-LINBIT / 1-877-454-6248
:
: http://www.linbit.com


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drbd-user mailing list
drbd-user@...
http://lists.linbit.com/mailman/listinfo/drbd-user

[Scott Inderlied]

I have a support agreement and therefore have access to the extended guide,
yet I can't find mention of xenserver specifics. I'm hitting my head against
the wall right now with SR's, LVM, and DRBD.

-----Original Message-----
From: drbd-user-bounces@...
[mailto:drbd-user-bounces@...] On Behalf Of Adam Gandelman
Sent: Sunday, October 18, 2009 17:32
To: drbd-user@...
Subject: Re: [DRBD-user] Citrix XenServer 5.5 + drbd for HA


Hi Ingmar-

DRBD can be used from within xenserver to replicate storage
repositories.  This is documented in our extended users guide.  You can
also use DRBD to build HA iSCSI/NFS clusters to serve HA SRs to an
entire xenserver pool.  However, HA on the VM level is the job of a
higher level cluster manager and, AFIK, this is either not possible to
do with OCF-based CRMs or nobody has developed it yet.  It is something
I plan on looking into in the coming months.  Citrix offers an
enterprise add-on for this but it does not provide any redundancy on the
storage level, so some other  form of shared storage (more $$) is
required.  If you need HA storage repositories for your xenserver domUs,
DRBD is a relatively easy "drop in" solution.

If you do not need or want the features of XenServer/XenCenter,
heartbeat/pacemaker can monitor OSS Xen domUs in addition to DRBD.
There is an Xen OCF script that is shipped with Pacemaker.

hope that helps
Adam



Beck Ingmar wrote:

> Hi,
>
> are there news regarding Citrix XenServer 5.5 and drdbd as HA solution?
> Florian told me some months ago that so far there is no known solution
> for this.
>
> Has someone already implemented this? Is there a guide / how-to for this
> solution?
>
> Is this solution better or worse than a HA-cluster with Xen-OS and
> drbd to
> eg Debian 5. What would be the advantages and disadvantages of this
> solution?
>
> regards
> Ingmar
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> drbd-user mailing list
> drbd-user@...
> http://lists.linbit.com/mailman/listinfo/drbd-user
>  

--
: Adam Gandelman
: Telephone: [phone] Ex. 203
: LINBIT | Your Way to High Availability
: Sales: 1-877-4-LINBIT / 1-877-454-6248
:
: http://www.linbit.com


_______________________________________________
drbd-user mailing list
drbd-user@...
http://lists.linbit.com/mailman/listinfo/drbd-user

_______________________________________________
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[Adam Gandelman-2]

Scott-

My mistake.  This is documented in the new DRBD Documentation Library,
not the extended users guide.

Basically, you can create LVM SRs on top of  a DRBD device or
reintroduce existing SRs as new, DRBD backed SRs.    Creating them
essentially creates a PV/VG stack for each SR/PBD on top of drbdX and
carves out LVs for each virtual drive.  When you get past the verbose xe
CLI commands and long UUIDs, you quickly realize its all just trivial
LVM stuff going on underneath.  

Again, this is  outlined in the Doc Library which is available through
the LINBIT support system.

--
Adam Gandelman - 503-573-1262
LINBIT - Your Way to High Availability
8152 SW Hall Blvd., Suite #209 : Beaverton, OR 97008

http://www.linbit.com


Scott Inderlied wrote:

> I have a support agreement and therefore have access to the extended guide,
> yet I can't find mention of xenserver specifics. I'm hitting my head against
> the wall right now with SR's, LVM, and DRBD.
>
> -----Original Message-----
> From: drbd-user-bounces@...
> [mailto:drbd-user-bounces@...] On Behalf Of Adam Gandelman
> Sent: Sunday, October 18, 2009 17:32
> To: drbd-user@...
> Subject: Re: [DRBD-user] Citrix XenServer 5.5 + drbd for HA
>
>
> Hi Ingmar-
>
> DRBD can be used from within xenserver to replicate storage
> repositories.  This is documented in our extended users guide.  You can
> also use DRBD to build HA iSCSI/NFS clusters to serve HA SRs to an
> entire xenserver pool.  However, HA on the VM level is the job of a
> higher level cluster manager and, AFIK, this is either not possible to
> do with OCF-based CRMs or nobody has developed it yet.  It is something
> I plan on looking into in the coming months.  Citrix offers an
> enterprise add-on for this but it does not provide any redundancy on the
> storage level, so some other  form of shared storage (more $$) is
> required.  If you need HA storage repositories for your xenserver domUs,
> DRBD is a relatively easy "drop in" solution.
>
> If you do not need or want the features of XenServer/XenCenter,
> heartbeat/pacemaker can monitor OSS Xen domUs in addition to DRBD.
> There is an Xen OCF script that is shipped with Pacemaker.
>
> hope that helps
> Adam
>
>
>
> Beck Ingmar wrote:
>  
>> Hi,
>>
>> are there news regarding Citrix XenServer 5.5 and drdbd as HA solution?
>> Florian told me some months ago that so far there is no known solution
>> for this.
>>
>> Has someone already implemented this? Is there a guide / how-to for this
>> solution?
>>
>> Is this solution better or worse than a HA-cluster with Xen-OS and
>> drbd to
>> eg Debian 5. What would be the advantages and disadvantages of this
>> solution?
>>
>> regards
>> Ingmar
>>
>> ------------------------------------------------------------------------
>>
>> _______________________________________________
>> drbd-user mailing list
>> drbd-user@...
>> http://lists.linbit.com/mailman/listinfo/drbd-user
>>  
>>    
>
>
>  

_______________________________________________
drbd-user mailing list
drbd-user@...
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