Torrey McMahon wrote: > Spencer Shepler wrote: > >> On Jul 10, 2008, at 7:05 AM, Ross wrote: >> >> >> >>> Oh god, I hope not. A patent on fitting a card in a PCI-E slot, or >>> using nvram with RAID (which raid controllers have been doing for >>> years) would just be rediculous. This is nothing more than cache, >>> and even with the American patent system I'd have though it hard to >>> get that past the obviousness test. >>> >>> >> How quickly they forget. >> >> Take a look at the Prestoserve User's Guide for a refresher... >> >> http://docs.sun.com/app/docs/doc/801-4896-11 >> > > Or Fast Write Cache > > http://docs.sun.com/app/docs/coll/fast-write-cache2.0 >
Yeah, the J-shaped scar just below my right shoulder blade... For the benefit of the alias, these sorts of products have a very limited market because they store state inside the server and use batteries. RAS guys hate batteries, especially those which are sitting on non-hot-pluggable I/O cards. While there are some specific cards which do allow hardware assisted remote replication (a previous Sun technology called "reflective memory" as used by VAXclusters) most of the issues are with serviceability and not availability. It is really bad juju to leave state in the wrong place during a service event. Where I think the jury is deadlocked is whether these are actually faster than RAID cards like http://www.sun.com/storagetek/storage_networking/hba/raid/ But from a performability perspective, the question is whether or not such cards perform significantly better than SSDs? Thoughts? -- richard _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
