This is perhaps off-topic too, but I have always wondered... > You might also want to look at getting a hardware RAID card or > daughterboard like the PERC-6i - these will allow you to set up a > RAID-10/50/60 that will stripe all data between two drives, giving you > another twofold speed increase. You probably want to make sure that your > card has battery backup if you care about your database - otherwise a > power cut can lose cached data rather painfully, even if you have a UPS. > If you're moderately paranoid, or your data is important, you should > disable on-drive write caching, as these never have battery backup - but > this will cost you some speed. (This is a software issue, though, and > won't affect your purchased configuration.)
I am curious as to why this type of battery-backed cache is important. The OS would do a large amount of caching (Linux can have a disk cache of many gigabytes) which I am sure would be far more effective than the small caches on many RAID cards. Given that the OS, if configured properly, should provide the best type of caching possible, why is it still necessary to have RAID cache and on-drive cache? Surely these would provide no additional benefit? Anyway, just something I've often wondered about :-) Cheers, Adam. _______________________________________________ Linux-PowerEdge mailing list Linux-PowerEdge@dell.com https://lists.us.dell.com/mailman/listinfo/linux-poweredge Please read the FAQ at http://lists.us.dell.com/faq
