[Lustre-discuss] Clustered MDS & OSS Servers

[Tina Friedrich]

Virtual IP will not work at all. We've tried it, though not for 
failover. Lustre basically implements/handles it's own networking, 
remember.

Tina

Jagga Soorma wrote:
> How would the OSS's and client's communicate with the MDS server in a 
> failover situation?
> 
> This is how I am doing things:
> 
> mds01: mkfs.lustre --fsname=fsname --mdt --mgs /dev/vgname/lvname
> 
> oss01: mkfs.lustre --ost --fsname=fsname --failnode=oss02 at o2ib3 
> --mgsnode=mds01 at o2ib3 /dev/mapper/mpath0
> oss02: mkfs.lustre --ost --fsname=fsname --failnode=oss01 at o2ib3 
> --mgsnode=mds01 at o2ib3 /dev/mapper/mpath0
> 
> client01: mount -t lustre mds01-ib at o2ib3:/fsname /mnt
> 
> Now, if mds01 fails over to mds02, how would the client communicate with 
> the new MDS server if the IP changes?
> 
> What would the mkfs.lustre commands look like for a HA setup for MDS & 
> OSS. 
> 
> Also, is there a downfall for using a virtual IP for the MDS's? 
> 
> Thanks in advance for your assistance.
> -J
> 
> 
> 
> On Tue, Jan 19, 2010 at 2:43 AM, Andreas Dilger <adilger at sun.com 
> <mailto:adilger at sun.com>> wrote:
> 
>     On 2010-01-19, at 13:01, Jagga Soorma wrote:
> 
>         I am working on clustering our MDS & OSS servers and wanted to
>         make sure I understand this correctly.  Can you please let me
>         know if this sounds right:
> 
>         a) Planning on having a floating virtual IP setup on the active
>         MDS server (ib1:1).  This is what the OSS's will use when doing
>         their mkfs.  In an outage this virtual IP address will migrate
>         to the standby node.
> 
> 
>     This is not how Lustre failover works.  You need to assign a
>     separate IP address for each MDS server.  Lustre handles multiple
>     MDS failover nodes itself.
> 
> 
>         b) On the oss's there is no need for a virtual IP that would
>         need to fail over in an outage.  I would simply have heartbeat
>         mount the filesystems on the other OSS node.
> 
> 
> 
>     Cheers, Andreas
>     --
>     Andreas Dilger
>     Sr. Staff Engineer, Lustre Group
>     Sun Microsystems of Canada, Inc.
> 
> 
> 
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-- 
Tina Friedrich, Computer Systems Administrator, Diamond Light Source Ltd
Diamond House, Harwell Science and Innovation Campus - 01235 77 8442