I've only been able to read the "Using SRDF/S with Celerra for Disaster Recovery" pdf so far which states that I need to contact EMC to get a copy of "Using MirrorView/Synchronous with Celerra for Disaster Recovery" which is fair enough.
sure. shouldnt be a problem to get it directly
also before it gets implemented your EMC guy has to file an RPQ to validate the environment
I was just trying to get an idea of how the failover between Celerras with synchronous replication wouldy work though.
sure - in short you would do a failover by issueing "nas_mview -activate" from the destination side
At that point your source side data movers would shut down, the destination side of the mirror gets activated and the remote standby data movers would boot using the very same config. That piece is very similar to a local failover from a primary to a standby data mover - it just takes longer The good thing is that its completely transparent - the client doesnt notice he's now talking to the other Celerra - also for CIFS, NFS and ISCSI
At the moment we are using Celerra replicator so failover requires manual intervention to failover the VDMs/filesystems so that they become r/w and there is always that chance of data loss. With synchronous replication there would be no data loss but would we still have to manually failover the VDMs/filesystems?
not each VDMfs separately but you would have to manually failover the whole Celerra with one command
Normally this is manual - however with the help of EMC professional services there are solutions with a 3rd site Linux or Windows box that monitor the Celerra and initiates a failover automatically.
I've only been able to read the "Using SRDF/S with Celerra for Disaster Recovery" pdf so far which states that I need to contact EMC to get a copy of "Using MirrorView/Synchronous with Celerra for Disaster Recovery" which is fair enough.
I was just trying to get an idea of how the failover between Celerras with synchronous replication would work though.
At the moment we are using Celerra replicator so failover requires manual intervention to failover the VDMs/filesystems so that they become r/w and there is always that chance of data loss.
With synchronous replication there would be no data loss but would we still have to manually failover the VDMs/filesystems?
However it works very differently from the Celerra Replicator. If you know Celerra and SRDF/S its a very similar setup
quick points - you need a MirrorView/S license on the Clariion's - only two Clariion's in use for that Celerra - one per NS gateway - box-failover - takes everything with it including IP and MAC addresses - all the data one a data mover has to be synchronously mirrored - not just one file system - the mirrored copy of the data is not available before a failover - no readonly access it - capacity has to be what fits within one Clariion consisteny group
There are two manuals on Powerlink describing it, but I suggest you discuss it with your EMC NAS specialist to see if its a fit for you.
Depending on the protocols you are using there might be other options. For example if you can use ISCSI then you can use a LVM or RepliStor to mirror.
Rainer_EMC
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December 11th, 2008 06:00
states that I need to contact EMC to get a copy of "Using MirrorView/Synchronous with Celerra for Disaster Recovery" which is fair enough.
sure. shouldnt be a problem to get it directly
also before it gets implemented your EMC guy has to file an RPQ to validate the environment
sure - in short you would do a failover by issueing "nas_mview -activate" from the destination side
At that point your source side data movers would shut down, the destination side of the mirror gets activated and the remote standby data movers would boot using the very same config.
That piece is very similar to a local failover from a primary to a standby data mover - it just takes longer
The good thing is that its completely transparent - the client doesnt notice he's now talking to the other Celerra - also for CIFS, NFS and ISCSI
VDMs/filesystems so that they become r/w and there is always that chance of data loss.
With synchronous replication there would be no data loss but would we still have to manually failover the VDMs/filesystems?
not each VDMfs separately but you would have to manually failover the whole Celerra with one command
Normally this is manual - however with the help of EMC professional services there are solutions with a 3rd site Linux or Windows box that monitor the Celerra and initiates a failover automatically.
sheppie
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108 Posts
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December 11th, 2008 04:00
I've only been able to read the "Using SRDF/S with Celerra for Disaster Recovery" pdf so far which states that I need to contact EMC to get a copy of "Using MirrorView/Synchronous with Celerra for Disaster Recovery" which is fair enough.
I was just trying to get an idea of how the failover between Celerras with synchronous replication would work though.
At the moment we are using Celerra replicator so failover requires manual intervention to failover the VDMs/filesystems so that they become r/w and there is always that chance of data loss.
With synchronous replication there would be no data loss but would we still have to manually failover the VDMs/filesystems?
Regards,
Sheppie
Rainer_EMC
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8.6K Posts
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December 11th, 2008 04:00
yes that's posssible.
However it works very differently from the Celerra Replicator.
If you know Celerra and SRDF/S its a very similar setup
quick points
- you need a MirrorView/S license on the Clariion's
- only two Clariion's in use for that Celerra - one per NS gateway
- box-failover - takes everything with it including IP and MAC addresses
- all the data one a data mover has to be synchronously mirrored - not just one file system
- the mirrored copy of the data is not available before a failover - no readonly access it
- capacity has to be what fits within one Clariion consisteny group
There are two manuals on Powerlink describing it, but I suggest you discuss it with your EMC NAS specialist to see if its a fit for you.
Depending on the protocols you are using there might be other options.
For example if you can use ISCSI then you can use a LVM or RepliStor to mirror.
sheppie
1 Rookie
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108 Posts
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December 11th, 2008 06:00
Sheppie