Hi Andreas, thanks for that. I'll follow with interest - though we only got our first Optane system to test rather recently.
Cheers, Dave -- ** Dave Holland ** Systems Support -- Informatics Systems Group ** ** 01223 496923 ** Wellcome Sanger Institute, Hinxton, UK ** On Mon, Jan 13, 2020 at 07:56:42PM +0000, Andreas Dilger wrote: > The most likely candidate for effectively using Optane/NVRAM would be > > via Persistent Client Cache (PCC), which allows client-local storage > to > > be part of the Lustre namespace. Files can be cached on a local > NVRAM > > device (managed by a local filesystem like ext4, or possibly > something > > more experimental like NOVA for better performance) and then migrated > > into the cache. > > Once the file is in PCC, it can be accessed via the local filesystem > > operations, including DAX, for very low-latency operations. See the > > presentation from LAD'19 for details: > > [1]https://www.eofs.eu/_media/events/lad19/07_li_xi-nvram_pcc.pdf > [eofs.eu] > > It should be noted that in Lustre 2.13, files in PCC are NOT resident > in the > > main filesystem, so if the client node goes offline then the files > will not be > > accessible until the client node is restarted. For some workloads > this is OK > > (e.g. files being generated locally with high IOPS that are > occasionally > > needed on other clients), but not for others. We will be improving > PCC to > > use FLR to mirror a copy into the client cache and still keep a copy > in the > > main filesystem, but that is not available yet. > > Cheers, Andreas > > On Jan 13, 2020, at 10:03, Dave Holland <[2][email protected]> wrote: > > I haven't been to LUG or LAD recently, so I'm a bit out of the loop, > but > how much use is Optane finding in the Lustre world? > The main obstacle I see is that it's server-local, so building a > resilient/failover-capable system isn't straightforward. > Thanks for any observations. > Cheers, > Dave > -- > ** Dave Holland ** Systems Support -- Informatics Systems Group ** > ** 01223 496923 ** Wellcome Sanger Institute, Hinxton, UK ** > > Cheers, Andreas > -- > Andreas Dilger > Principal Lustre Architect > Whamcloud > > References > > 1. > https://urldefense.proofpoint.com/v2/url?u=https-3A__www.eofs.eu_-5Fmedia_events_lad19_07-5Fli-5Fxi-2Dnvram-5Fpcc.pdf&d=DwMFAg&c=D7ByGjS34AllFgecYw0iC6Zq7qlm8uclZFI0SqQnqBo&r=64bKjxgut4Pa0xs5b84yPg&m=H2vGJE5te4vZmLD2u-for6b7tPd0hqJ5ZGK1KCJW1PA&s=65AxT6uau9wbcX-T0aEFtfzXX-iIrAw-K1SlVCjJ4oY&e= > 2. mailto:[email protected] -- The Wellcome Sanger Institute is operated by Genome Research Limited, a charity registered in England with number 1021457 and a company registered in England with number 2742969, whose registered office is 215 Euston Road, London, NW1 2BE. _______________________________________________ lustre-discuss mailing list [email protected] http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
