Thanks Vic&Simon, I’m totally cool with “it depends” the solution guidance is to achieve a Highly Available FS. And there is Dark Fibre between the two locations. FileNet is the application and they want two things. Ability to write in both locations (maybe close to at the same time not necessarily the same files though) and protect against any site failure. So in my mind my Scenario 1 would work as long as I had copies=2 and restripe are acceptable. Is my Scenario 2 I would still have to restripe if the SAN in site 1 went down.
I’m looking for the simplest approach that provides the greatest availability. From: <[email protected]> on behalf of "Simon Thompson (Research Computing - IT Services)" <[email protected]> Reply-To: gpfsug main discussion list <[email protected]> Date: Thursday, July 21, 2016 at 8:02 AM To: gpfsug main discussion list <[email protected]> Subject: Re: [gpfsug-discuss] NDS in Two Site scenario It depends. What are you protecting against? Either will work depending on your acceptable failure modes. I'm assuming here that you are using copies=2 to replicate the data, and that the NSD devices have different failure groups per site. In the second example, if you were to lose the NSD servers in Site 1, but not the SAN, you would continue to have 2 copies of data written as the NSD servers in Site 2 could write to the SAN in Site 1. In the first example you would need to rest ripe the file-system when brining the Site 1 back online to ensure data is replicated.\ Simon From: <[email protected]<mailto:[email protected]>> on behalf of "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Reply-To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Date: Thursday, 21 July 2016 at 13:45 To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: Re: [gpfsug-discuss] NDS in Two Site scenario This is where my confusion sits. So if I have two sites, and two NDS Nodes per site with 1 NSD (to keep it simple), do I just present the physical LUN in Site1 to Site1 NDS Nodes and physical LUN in Site2 to Site2 NSD Nodes? Or is it that I present physical LUN in Site1 to all 4 NDS Nodes and the same at Site2? (Assuming SAN and not direct attached in this case). I know I’m being persistent but this for some reason confuses me. Site1 NSD Node1 ---NSD1 ---Physical LUN1 from SAN1 NSD Node2 Site2 NSD Node3 ---NSD2 –Physical LUN2 from SAN2 NSD Node4 Or Site1 NSD Node1 ----NSD1 –Physical LUN1 from SAN1 ----NSD2 –Physical LUN2 from SAN2 NSD Node2 Site 2 NSD Node3 ---NSD2 – Physical LUN2 from SAN2 ---NSD1 --Physical LUN1 from SAN1 NSD Node4 Site 3 Node5 Quorum From: <[email protected]<mailto:[email protected]>> on behalf of Ken Hill <[email protected]<mailto:[email protected]>> Reply-To: gpfsug main discussion list <[email protected]<mailto:[email protected]>> Date: Wednesday, July 20, 2016 at 7:02 PM To: gpfsug main discussion list <[email protected]<mailto:[email protected]>> Subject: Re: [gpfsug-discuss] NDS in Two Site scenario Yes - it is a cluster. The sites should NOT be further than a MAN - or Campus network. If you're looking to do this over a large distance - it would be best to choose another GPFS solution (Multi-Cluster, AFM, etc). Regards, Ken Hill Technical Sales Specialist | Software Defined Solution Sales IBM Systems ________________________________ Phone:1-540-207-7270 E-mail: [email protected]<mailto:[email protected]> [cid:[email protected]]<http://www.ibm.com/us-en/> [cid:[email protected]] <http://www-03.ibm.com/systems/platformcomputing/products/lsf/> [cid:[email protected]] <http://www-03.ibm.com/systems/platformcomputing/products/high-performance-services/index.html> [cid:[email protected]] <http://www-03.ibm.com/systems/platformcomputing/products/symphony/index.html> [cid:[email protected]] <http://www-03.ibm.com/systems/storage/spectrum/> [cid:[email protected]] <http://www-01.ibm.com/software/tivoli/csi/cloud-storage/> [cid:[email protected]] <http://www-01.ibm.com/software/tivoli/csi/backup-recovery/> [cid:[email protected]] <http://www-03.ibm.com/systems/storage/tape/ltfs/index.html> [cid:[email protected]] <http://www-03.ibm.com/systems/storage/spectrum/> [cid:[email protected]] <http://www-03.ibm.com/systems/storage/spectrum/scale/> [cid:[email protected]] <https://www.ibm.com/marketplace/cloud/object-storage/us/en-us> 2300 Dulles Station Blvd Herndon, VA 20171-6133 United States From: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> To: gpfsug main discussion list <[email protected]<mailto:[email protected]>> Date: 07/20/2016 07:33 PM Subject: Re: [gpfsug-discuss] NDS in Two Site scenario Sent by: [email protected]<mailto:[email protected]> ________________________________ So in this scenario Ken, can server3 see any disks in site1? From: <[email protected]<mailto:[email protected]>> on behalf of Ken Hill <[email protected]<mailto:[email protected]>> Reply-To: gpfsug main discussion list <[email protected]<mailto:[email protected]>> Date: Wednesday, July 20, 2016 at 4:15 PM To: gpfsug main discussion list <[email protected]<mailto:[email protected]>> Subject: Re: [gpfsug-discuss] NDS in Two Site scenario Site1 Site2 Server1 (quorum 1) Server3 (quorum 2) Server2 Server4 SiteX Server5 (quorum 3) You need to set up another site (or server) that is at least power isolated (if not completely infrastructure isolated) from Site1 or Site2. You would then set up a quorum node at that site | location. This insures you can still access your data even if one of your sites go down. You can further isolate failure by increasing quorum (odd numbers). The way quorum works is: The majority of the quorum nodes need to be up to survive an outage. - With 3 quorum nodes you can have 1 quorum node failures and continue filesystem operations. - With 5 quorum nodes you can have 2 quorum node failures and continue filesystem operations. - With 7 quorum nodes you can have 3 quorum node failures and continue filesystem operations. - etc Please see http://www.ibm.com/support/knowledgecenter/en/STXKQY_4.2.0/ibmspectrumscale42_content.html?view=kcfor more information about quorum and tiebreaker disks. Ken Hill Technical Sales Specialist | Software Defined Solution Sales IBM Systems ________________________________ Phone:1-540-207-7270 E-mail: [email protected]<mailto:[email protected]> [cid:[email protected]]<http://www.ibm.com/us-en/> [cid:[email protected]] <http://www-03.ibm.com/systems/platformcomputing/products/lsf/> [cid:[email protected]] <http://www-03.ibm.com/systems/platformcomputing/products/high-performance-services/index.html> [cid:[email protected]] <http://www-03.ibm.com/systems/platformcomputing/products/symphony/index.html> [cid:[email protected]] <http://www-03.ibm.com/systems/storage/spectrum/> [cid:[email protected]] <http://www-01.ibm.com/software/tivoli/csi/cloud-storage/> [cid:[email protected]] <http://www-01.ibm.com/software/tivoli/csi/backup-recovery/> [cid:[email protected]] <http://www-03.ibm.com/systems/storage/tape/ltfs/index.html> [cid:[email protected]] <http://www-03.ibm.com/systems/storage/spectrum/> [cid:[email protected]] <http://www-03.ibm.com/systems/storage/spectrum/scale/> [cid:[email protected]] <https://www.ibm.com/marketplace/cloud/object-storage/us/en-us> 2300 Dulles Station Blvd Herndon, VA 20171-6133 United States From: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> To: gpfsug main discussion list <[email protected]<mailto:[email protected]>> Date: 07/20/2016 04:47 PM Subject: [gpfsug-discuss] NDS in Two Site scenario Sent by: [email protected]<mailto:[email protected]> ________________________________ For some reason this concept is a round peg that doesn’t fit the square hole inside my brain. Can someone please explain the best practice to setting up two sites same cluster? I get that I would likely have two NDS nodes in site 1 and two NDS nodes in site two. What I don’t understand are the failure scenarios and what would happen if I lose one or worse a whole site goes down. Do I solve this by having scale replication set to 2 for all my files? I mean a single site I think I get it’s when there are two datacenters and I don’t want two clusters typically. Mark R. Bush| Solutions Architect Mobile: 210.237.8415 | [email protected]<mailto:[email protected]> Sirius Computer Solutions | www.siriuscom.com<http://www.siriuscom.com/> 10100 Reunion Place, Suite 500, San Antonio, TX 78216 This message (including any attachments) is intended only for the use of the individual or entity to which it is addressed and may contain information that is non-public, proprietary, privileged, confidential, and exempt from disclosure under applicable law. If you are not the intended recipient, you are hereby notified that any use, dissemination, distribution, or copying of this communication is strictly prohibited. This message may be viewed by parties at Sirius Computer Solutions other than those named in the message header. This message does not contain an official representation of Sirius Computer Solutions. If you have received this communication in error, notify Sirius Computer Solutions immediately and (i) destroy this message if a facsimile or (ii) delete this message immediately if this is an electronic communication. Thank you. Sirius Computer Solutions<http://www.siriuscom.com/>_______________________________________________ gpfsug-discuss mailing list gpfsug-discuss at spectrumscale.org http://gpfsug.org/mailman/listinfo/gpfsug-discuss _______________________________________________ gpfsug-discuss mailing list gpfsug-discuss at spectrumscale.org http://gpfsug.org/mailman/listinfo/gpfsug-discuss
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