For non-stretch clusters, I think best practice would be to have an administrator analyze the situation and understand why the NSD was considered unavailable before attempting to start the disks back in the file system. Down NSDs are usually indicative of a serious issue.
However I have seen a transient network communication problems or NSD server recovery cause a NSD Client to report a NSD as failed. I would prefer that the FS manager check first that the NSDs are actually not accessible and that there isn’t a recovery operation within the NSD Servers supporting an NSD before marking NSDs as down. Recovery should be allowed to complete and a NSD client should just wait for that to happen. NSDs being marked down can cause serious file system outages!! We’ve also requested that a settable retry configuration setting be provided to have NSD Clients retry access to the NSD before reporting the NSD as failed (https://www.ibm.com/developerworks/rfe/execute?use_case=viewRfe&CR_ID=104474 if you want to add a vote!). Cheers, -Bryan From: gpfsug-discuss-boun...@spectrumscale.org [mailto:gpfsug-discuss-boun...@spectrumscale.org] On Behalf Of Jan-Frode Myklebust Sent: Wednesday, August 09, 2017 7:23 AM To: gpfsug main discussion list <gpfsug-discuss@spectrumscale.org> Subject: Re: [gpfsug-discuss] Is GPFS starting NSDs automatically? Note: External Email ________________________________ If you do a "mmchconfig restripeOnDiskFailure=yes", such a callback will be added for node-join events. That can be quite useful for stretched clusters, where you want to replicate all blocks to both locations, and this way recover automatically. -jf On Wed, Aug 9, 2017 at 2:14 PM, Oesterlin, Robert <robert.oester...@nuance.com<mailto:robert.oester...@nuance.com>> wrote: By default, GPFS does not automatically start down disks. You could add a callback “downdisk” via mmaddcallback that could trigger a “mmchdisk start” if you wanted. If a disk is marked down, it’s better to determine why before trying to start it as it may involve other issues that need investigation. Bob Oesterlin Sr Principal Storage Engineer, Nuance From: <gpfsug-discuss-boun...@spectrumscale.org<mailto:gpfsug-discuss-boun...@spectrumscale.org>> on behalf of "tomasz.wol...@ts.fujitsu.com<mailto:tomasz.wol...@ts.fujitsu.com>" <tomasz.wol...@ts.fujitsu.com<mailto:tomasz.wol...@ts.fujitsu.com>> Reply-To: gpfsug main discussion list <gpfsug-discuss@spectrumscale.org<mailto:gpfsug-discuss@spectrumscale.org>> Date: Wednesday, August 9, 2017 at 6:33 AM To: "gpfsug-discuss@spectrumscale.org<mailto:gpfsug-discuss@spectrumscale.org>" <gpfsug-discuss@spectrumscale.org<mailto:gpfsug-discuss@spectrumscale.org>> Subject: [EXTERNAL] [gpfsug-discuss] Is GPFS starting NSDs automatically? Does GPFS start “down” disks in a filesystem automatically? For instance, when connection to NSD is recovered, but it the meantime disk was put in “down” state by GPFS. Will GPFS in such case start the disk? _______________________________________________ gpfsug-discuss mailing list gpfsug-discuss at spectrumscale.org<http://spectrumscale.org> http://gpfsug.org/mailman/listinfo/gpfsug-discuss ________________________________ Note: This email is for the confidential use of the named addressee(s) only and may contain proprietary, confidential or privileged information. If you are not the intended recipient, you are hereby notified that any review, dissemination or copying of this email is strictly prohibited, and to please notify the sender immediately and destroy this email and any attachments. Email transmission cannot be guaranteed to be secure or error-free. The Company, therefore, does not make any guarantees as to the completeness or accuracy of this email or any attachments. This email is for informational purposes only and does not constitute a recommendation, offer, request or solicitation of any kind to buy, sell, subscribe, redeem or perform any type of transaction of a financial product.
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