don´t forget that you can use ramdisks.... just read how to select the right memory, and the right position before initialize you ramdisk 2011/1/19 Roberto Spadim <roberto@xxxxxxxxxxxxx>: > 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 > -- 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
