ok, your hardware have: cpu, memory, disk controller, disks and you computer have: cpu, memory, disk controler (your hardware) if your computer cache don´t sync to your disk controller you will lose information.... check that *memory, is the volatille memory and *disk controller is the non volatille memory if you tell me that you will never have a *memory, and you have always a non volatille memory, no problem, you will never need a kernel load... just a boot loader that read previous memory information and start in that point... why don´t do this? non volatille memory is not as fast as volatille memory got the problem? 2011/1/19 Cory Coager <ccoager@xxxxxxxxx>: > On Wed, Jan 19, 2011 at 01:19:18PM -0200, Roberto Spadim wrote: >> ok, >> but if you don?t sync file system (remove from memory and put in disk >> controller) >> you will lost information with or without a batery >> >> how to don?t lose information? >> don?t power down you memory,cpu, disk controller (sata controler, raid >> controller, or anyother) and disks (does it have a batery? a super >> capacitor?) >> if you power down, be sure that all memory was send to disk controller >> and that disk controller have energy (batery or capacitor) to send >> information to disks (they need batery or capacitor too) >> >> right? >> so, a ups can power cpu, memory, disk controller and disks with only >> one batery (not a batery for each device cpu,memory,disk,disk >> controller) >> the best world could be a non volatile memory (250mb/s flash 4kb >> block) with the speed of volatile memory (10000mb/s ddr3 i don?t know >> the block size) > > It would have to work the same as a hardware RAID controller. > Information is first written to the cache then synced to the > disk. If the data is in the cache but not on the disk, the > machine loses power, next boot up the software raid would need a > way to flush the data from the ram disk to the disk. Of course > this would require the battery be in working condition, as with > any hardware. > > Hopefully I've explained that well enough. Perhaps it will be > better to see the hardware I'm talking about: > http://techreport.com/articles.x/16255 > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Roberto Spadim Spadim Technology / SPAEmpresarial -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
