Hi, Without going into to much details, AFAIR, Ontap integrate NVRAM into the NFS write cache ( as it was developed as a NAS product). Ontap is using the STABLE bit which kind of tell the client "hey, I have no write cache at all, everything is written to stable storage - thus, don't bother with commits ( sync) commands - they are meaningless".
Regards, Tomer Perry Scalable I/O Development (Spectrum Scale) email: [email protected] 1 Azrieli Center, Tel Aviv 67021, Israel Global Tel: +1 720 3422758 Israel Tel: +972 3 9188625 Mobile: +972 52 2554625 From: "Keigo Matsubara" <[email protected]> To: gpfsug main discussion list <[email protected]> Date: 17/10/2018 16:35 Subject: Re: [gpfsug-discuss] Preliminary conclusion: single client, single thread, small files - native Scale vs NFS Sent by: [email protected] I also wonder how many products actually exploit NFS async mode to improve I/O performance by sacrificing the file system consistency risk: [email protected] wrote on 2018/10/17 22:26:52: > Using this option usually improves performance, but at > the cost that an unclean server restart (i.e. a crash) can cause > data to be lost or corrupted." For instance, NetApp, at the very least FAS 3220 running Data OnTap 8.1.2p4 7-mode which I tested with, would forcibly *promote* async mode to sync mode. Promoting means even if NFS client requests async mount mode, the NFS server ignores and allows only sync mount mode. Best Regards, --- Keigo Matsubara, Storage Solutions Client Technical Specialist, IBM Japan TEL: +81-50-3150-0595, T/L: 6205-0595 _______________________________________________ gpfsug-discuss mailing list gpfsug-discuss at spectrumscale.org http://gpfsug.org/mailman/listinfo/gpfsug-discuss
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