> > Hi all > > > > Is there anything usable for zfs/openindiana that allows for > > multi-tiered storage? > > > > The scenario is as thus: We have a 50TB storage unit which was built > > to be an archive, but lately, scientists have been using this for a > > fileserver for modelling. Pracitaclly, this means 50+ processes > > doing more or less random i/o to the server, which a 4-VDEV RAIDz2 > > system isn't very well suited to handle. Since we don't have > > sufficient storage to move the data they are modelling, we consider > > getting a bunch of SSDs for L2ARC/SLOG, which may solve the problem. > > But then, a better solution might be a two-tier storage solution, > > with fast drives on a server in front and slowish drives in the > > back. Such systems exists, but most of them are commercially built, > > meaning the price per terabyte will be about 5-10x the price of > > using ZFS on an open system. > > This sounds almost exactly like the sort of problem SSDs and > SLOG/L2ARC are designed for.
Not really, no. SLOG/L2ARC is fine for small amounts of data, but if you have 50TB or even more, where perhaps 10% are used more or less regularly, then those SSDs are likely to cost a wee bit. Tiered storage or hierarchical storage management ensures that data is available, but not necessarily from the fastest medium. I remember Novell had a solution for this using tape, and although that's not really current, it's the same idea. What I'm looking for is something like this: Slow server in the back with 50-100TB or so, RAIDz2 on lots of 7k2 drives. Fast server in the front with, say, 5-10TB on striped mirrores of 15k drives. But then again, I just wrote a spreadsheet to check how much it'll cost for 5TB on a dedicated server on 15k drives and compared that to 5TB worth of L2ARC on Crucial^WMicron RealSSD 256MB, and found the two to be so close in cost, they're basically equal, so I guess I'll rest my case on this :P Vennlige hilsener / Best regards roy -- Roy Sigurd Karlsbakk (+47) 97542685 r...@karlsbakk.net http://blogg.karlsbakk.net/ -- I all pedagogikk er det essensielt at pensum presenteres intelligibelt. Det er et elementært imperativ for alle pedagoger å unngå eksessiv anvendelse av idiomer med fremmed opprinnelse. I de fleste tilfeller eksisterer adekvate og relevante synonymer på norsk. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
