3:26 a.m.
Dear Team,
Can any one mention what are the disadvantages of having MDS and MDT
configured on a single server compared to configuration of having MGS and
MDT on different servers.
Thanks & Regards,
Narsimha.
5:33 p.m.
The main disadvantage today is that if the MGS is on the same server as the MDS, then if
that node fails it isn't possible to use "Imperative Recovery", where the
MGS notifies clients that the MDS has restarted. Instead, this would mean that the
clients need to time out their most recent RPC/ping before they notice the MDS has
failed.
That could increases recovery time by 100s or longer, depending on the number of clients
in the system. If faster recovery is less of an issue than having a dedicated MGS node,
then it is fine to have them on a single node. Note also that the MGS could run on the
backup MDS to avoid the need to have a dedicated MGS node.
Cheers, Andreas
--
Andreas Dilger
Lustre Software Architect
Intel High Performance Data Division
On 2015/10/05, 10:26 AM, "HPDD-discuss on behalf of Narsimha Reddy"
<hpdd-discuss-bounces@lists.01.org<mailto:hpdd-discuss-bounces@lists.01.org> on
behalf of narsimhalocuz@gmail.com<mailto:narsimhalocuz@gmail.com>> wrote:
Dear Team,
Can any one mention what are the disadvantages of having MDS and MDT configured on a
single server compared to configuration of having MGS and MDT on different servers.
Thanks & Regards,
Narsimha.
6:23 p.m.
Hi Andreas,
Can MGS be replicated?
Regards,
Cuong
On Tue, Oct 6, 2015 at 3:33 PM, Dilger, Andreas <andreas.dilger(a)intel.com>
wrote:
The main disadvantage today is that if the MGS is on the same server
as
the MDS, then if that node fails it isn't possible to use "Imperative
Recovery", where the MGS notifies clients that the MDS has restarted.
Instead, this would mean that the clients need to time out their most
recent RPC/ping before they notice the MDS has failed.
That could increases recovery time by 100s or longer, depending on the
number of clients in the system. If faster recovery is less of an issue
than having a dedicated MGS node, then it is fine to have them on a single
node. Note also that the MGS could run on the backup MDS to avoid the
need to have a dedicated MGS node.
Cheers, Andreas
--
Andreas Dilger
Lustre Software Architect
Intel High Performance Data Division
On 2015/10/05, 10:26 AM, "HPDD-discuss on behalf of Narsimha Reddy" <
hpdd-discuss-bounces@lists.01.org<mailto:hpdd-discuss-bounces@lists.01.org>
on behalf of narsimhalocuz@gmail.com<mailto:narsimhalocuz@gmail.com>>
wrote:
Dear Team,
Can any one mention what are the disadvantages of having MDS and MDT
configured on a single server compared to configuration of having MGS and
MDT on different servers.
Thanks & Regards,
Narsimha.
_______________________________________________
HPDD-discuss mailing list
HPDD-discuss(a)lists.01.org
https://lists.01.org/mailman/listinfo/hpdd-discuss
--
Nguyen Viet Cuong
2:51 a.m.
Cuong,
That depends on what you mean. It's not possible to have two active MGS
servers, but it is possible to configure MGS failover in an
active-passive manner. The Lustre manual (and various places online)
have more information.
- Patrick
On 10/06/2015 02:23 AM, Nguyen Viet Cuong wrote:
Hi Andreas,
Can MGS be replicated?
Regards,
Cuong
On Tue, Oct 6, 2015 at 3:33 PM, Dilger, Andreas
<andreas.dilger(a)intel.com <mailto:andreas.dilger@intel.com>> wrote:
The main disadvantage today is that if the MGS is on the same
server as the MDS, then if that node fails it isn't possible to
use "Imperative Recovery", where the MGS notifies clients that the
MDS has restarted. Instead, this would mean that the clients need
to time out their most recent RPC/ping before they notice the MDS
has failed.
That could increases recovery time by 100s or longer, depending on
the number of clients in the system. If faster recovery is less
of an issue than having a dedicated MGS node, then it is fine to
have them on a single node. Note also that the MGS could run on
the backup MDS to avoid the need to have a dedicated MGS node.
Cheers, Andreas
--
Andreas Dilger
Lustre Software Architect
Intel High Performance Data Division
On 2015/10/05, 10:26 AM, "HPDD-discuss on behalf of Narsimha
Reddy" <hpdd-discuss-bounces(a)lists.01.org
<mailto:hpdd-discuss-bounces@lists.01.org><mailto:hpdd-discuss-bounces@lists.01.org
<mailto:hpdd-discuss-bounces@lists.01.org>> on behalf of
narsimhalocuz(a)gmail.com
<mailto:narsimhalocuz@gmail.com><mailto:narsimhalocuz@gmail.com
<mailto:narsimhalocuz@gmail.com>>> wrote:
Dear Team,
Can any one mention what are the disadvantages of having MDS and
MDT configured on a single server compared to configuration of
having MGS and MDT on different servers.
Thanks & Regards,
Narsimha.
_______________________________________________
HPDD-discuss mailing list
HPDD-discuss(a)lists.01.org <mailto:HPDD-discuss@lists.01.org>
https://lists.01.org/mailman/listinfo/hpdd-discuss
--
Nguyen Viet Cuong
_______________________________________________
HPDD-discuss mailing list
HPDD-discuss(a)lists.01.org
https://lists.01.org/mailman/listinfo/hpdd-discuss
3:31 p.m.
Hi Patrick,
Thanks! I have just found some.
Cuong
On Wed, Oct 7, 2015 at 12:51 AM, Patrick Farrell <paf(a)cray.com> wrote:
Cuong,
That depends on what you mean. It's not possible to have two active MGS
servers, but it is possible to configure MGS failover in an active-passive
manner. The Lustre manual (and various places online) have more
information.
- Patrick
On 10/06/2015 02:23 AM, Nguyen Viet Cuong wrote:
Hi Andreas,
Can MGS be replicated?
Regards,
Cuong
On Tue, Oct 6, 2015 at 3:33 PM, Dilger, Andreas <andreas.dilger(a)intel.com>
wrote:
> The main disadvantage today is that if the MGS is on the same server as
> the MDS, then if that node fails it isn't possible to use "Imperative
> Recovery", where the MGS notifies clients that the MDS has restarted.
> Instead, this would mean that the clients need to time out their most
> recent RPC/ping before they notice the MDS has failed.
>
> That could increases recovery time by 100s or longer, depending on the
> number of clients in the system. If faster recovery is less of an issue
> than having a dedicated MGS node, then it is fine to have them on a single
> node. Note also that the MGS could run on the backup MDS to avoid the
> need to have a dedicated MGS node.
>
> Cheers, Andreas
> --
> Andreas Dilger
> Lustre Software Architect
> Intel High Performance Data Division
>
> On 2015/10/05, 10:26 AM, "HPDD-discuss on behalf of Narsimha Reddy" <
> hpdd-discuss-bounces(a)lists.01.org<mailto:
> hpdd-discuss-bounces(a)lists.01.org> on behalf of narsimhalocuz(a)gmail.com
> <mailto:narsimhalocuz@gmail.com>> wrote:
>
> Dear Team,
>
> Can any one mention what are the disadvantages of having MDS and MDT
> configured on a single server compared to configuration of having MGS and
> MDT on different servers.
>
> Thanks & Regards,
> Narsimha.
> _______________________________________________
> HPDD-discuss mailing list
> HPDD-discuss(a)lists.01.org
> https://lists.01.org/mailman/listinfo/hpdd-discuss
>
--
Nguyen Viet Cuong
_______________________________________________
HPDD-discuss mailing
listHPDD-discuss@lists.01.orghttps://lists.01.org/mailman/listinfo/hpdd-discuss
_______________________________________________
HPDD-discuss mailing list
HPDD-discuss(a)lists.01.org
https://lists.01.org/mailman/listinfo/hpdd-discuss
--
Nguyen Viet Cuong
12:25 a.m.
Hi Andreas,
Thank you for the reply.
So that indicates if the node that containing MGS & MDS fails then it will
affect a 100sec delay to come online than normal.
But what is the performance differences that we can observe between the MGS
& MDS on same node and 2 servers with MGS & MDS configured.
Thanks,
Narsimha.
On Tue, Oct 6, 2015 at 12:03 PM, Dilger, Andreas <andreas.dilger(a)intel.com>
wrote:
The main disadvantage today is that if the MGS is on the same server
as
the MDS, then if that node fails it isn't possible to use "Imperative
Recovery", where the MGS notifies clients that the MDS has restarted.
Instead, this would mean that the clients need to time out their most
recent RPC/ping before they notice the MDS has failed.
That could increases recovery time by 100s or longer, depending on the
number of clients in the system. If faster recovery is less of an issue
than having a dedicated MGS node, then it is fine to have them on a single
node. Note also that the MGS could run on the backup MDS to avoid the
need to have a dedicated MGS node.
Cheers, Andreas
--
Andreas Dilger
Lustre Software Architect
Intel High Performance Data Division
On 2015/10/05, 10:26 AM, "HPDD-discuss on behalf of Narsimha Reddy" <
hpdd-discuss-bounces(a)lists.01.org on behalf of narsimhalocuz(a)gmail.com>
wrote:
Dear Team,
Can any one mention what are the disadvantages of having MDS and MDT
configured on a single server compared to configuration of having MGS and
MDT on different servers.
Thanks & Regards,
Narsimha.
9:32 a.m.
There should be no performance difference at all. The MGS doesn't really do anything
today except when clients or servers are mounting/unmounting/failing.
Cheers, Andreas
--
Andreas Dilger
Lustre Software Architect
Intel High Performance Data Division
On 2015/10/09, 7:25 AM, "Narsimha Reddy"
<narsimhalocuz@gmail.com<mailto:narsimhalocuz@gmail.com>> wrote:
Hi Andreas,
Thank you for the reply.
So that indicates if the node that containing MGS & MDS fails then it will affect a
100sec delay to come online than normal.
But what is the performance differences that we can observe between the MGS & MDS on
same node and 2 servers with MGS & MDS configured.
Thanks,
Narsimha.
On Tue, Oct 6, 2015 at 12:03 PM, Dilger, Andreas
<andreas.dilger@intel.com<mailto:andreas.dilger@intel.com>> wrote:
The main disadvantage today is that if the MGS is on the same server as the MDS, then if
that node fails it isn't possible to use "Imperative Recovery", where the
MGS notifies clients that the MDS has restarted. Instead, this would mean that the
clients need to time out their most recent RPC/ping before they notice the MDS has
failed.
That could increases recovery time by 100s or longer, depending on the number of clients
in the system. If faster recovery is less of an issue than having a dedicated MGS node,
then it is fine to have them on a single node. Note also that the MGS could run on the
backup MDS to avoid the need to have a dedicated MGS node.
Cheers, Andreas
--
Andreas Dilger
Lustre Software Architect
Intel High Performance Data Division
On 2015/10/05, 10:26 AM, "HPDD-discuss on behalf of Narsimha Reddy"
<hpdd-discuss-bounces@lists.01.org<mailto:hpdd-discuss-bounces@lists.01.org> on
behalf of narsimhalocuz@gmail.com<mailto:narsimhalocuz@gmail.com>> wrote:
Dear Team,
Can any one mention what are the disadvantages of having MDS and MDT configured on a
single server compared to configuration of having MGS and MDT on different servers.
Thanks & Regards,
Narsimha.
2536
days inactive
2540
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6 comments
4 participants
participants (4)
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Dilger, Andreas -
Narsimha Reddy -
Nguyen Viet Cuong -
Patrick Farrell