Hi Shankar, Vic, Would it not be possible, once the original cache site is useable, to bring it up in local-update mode so that you can pre-fetch all the metadata from home?
Once you are ready to do the switchover: stop writing to home, do a final sync of metadata, then “promote” the local-update cache to a single-writer; continue writing new data in to the original cache. I am assuming the only reason you’d want to repopulate the SW cache with metadata is to prevent someone accidentally creating the same file after the disaster and overwriting the original at home without any knowledge? Cheers, Luke. From: [email protected] [mailto:[email protected]] On Behalf Of Shankar Balasubramanian Sent: 19 April 2016 06:47 To: gpfsug main discussion list <[email protected]> Subject: Re: [gpfsug-discuss] AFM Question SW mode does not support failover. IW does, so this will not work. Best Regards, Shankar Balasubramanian AFM & Async DR Development IBM Systems Bangalore - Embassy Golf Links India From: Vic Cornell <[email protected]<mailto:[email protected]>> To: gpfsug main discussion list <[email protected]<mailto:[email protected]>> Date: 04/18/2016 07:13 PM Subject: [gpfsug-discuss] AFM Question Sent by: [email protected]<mailto:[email protected]> ________________________________ Hi All, Is there a bandwidth efficient way (downtime is allowed) to reverse the relationship between HOME and CACHE in a single writer AFM relationship? If it is not immediately obvious why this might be useful, see the following scenario: Fileset A is a GPFS fileset which is acting as CACHE for a single writer HOME on fileset B located on a separate filesystem. The system hosting A fails and all data on fileset A is lost. Admin uses fileset B as a recovery volume and users read and write data to B until the system hosting A is recovered, albeit without data. Admin uses mmafmctl to “failover” AFM relationship to a new fileset on A, all data are copied from B to A over time and users continue to access the data via B. So is there a bandwidth efficient way (downtime is allowed) to reverse the relationship between A and B such that the replication flow is as it was to start with? Cheers, Vic _______________________________________________ gpfsug-discuss mailing list gpfsug-discuss at spectrumscale.org http://gpfsug.org/mailman/listinfo/gpfsug-discuss The Francis Crick Institute Limited is a registered charity in England and Wales no. 1140062 and a company registered in England and Wales no. 06885462, with its registered office at 215 Euston Road, London NW1 2BE.
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