Some guidance, please

FAQ, getting help, user experience about FancyCache
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Re: Some guidance, please

Post by dustyny »

Manny I'm a bit reluctant to answer you... However I was a bit vague..

I've tested this extensively and I know for a fact that fancycache works via SMB. I've used it this way everyday for the past year and I get hit rates of 100% with transfers averaging 4GBs (love my 40Gbs network).

SMB is a networking protocol and it sits on a different layer of the OS stack then the storage system. SMB can be switched out for any networking protocol (FTP, CIFS, NetBios, NFS, AppleTalk) and it doesn't make any difference to FancyCache or Windows (other than overhead costs). The networking/file-sharing protocol will make requests for data that will be filled by the storage system. If the data is in the cache, Fancycache it will fulfill the request through the storage system.

The only way you will see FancyCache directly affected by SMB is if you create a VHD(x) on a SMB share and you mount it across the network. Fancycache will see the mounted (VHD) drive and it will be available for caching. However there is no point to do this unless you are running at least a 10Gb network (1GB wirespeed) with RDMA and a Win8-2012 (SMB3) fileserver, as Win7-2008r2 SMB2.1 has high latency penalties and huge overhead costs..
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Re: Some guidance, please

Post by Lawnmower1 »

That's right, Manny. I configured FC on the server side, so in theory, network accesses to the shared resource should have been cached.

Concerning the requirement for TGE: Not true. The "problem" application reads small parts of every file. All 50K of them. In this case, those frequently-accessed blocks are cached and served up at SSD speeds. The difference here is access time on SSD v. access time on HDD for those 50K files. The speed of the Ethernet isn't a factor AT ALL. "Disk" access time IS, and serving those small blocks out of an SSD that can manage 60,000 IOPS makes a huge, order of magnitude (if not more), difference.
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