AKSYS Tech Pty Ltd wrote: > Hi Guys > > > > Thanks very much for all the info. > > I must confess that this is my first time playing with Linux so it is > all a bit new to me. > > I am trying to make a solid “Industrial” controller, because as a day > job I retrofit and repair CNC machine tools. And as a result of this I > see many hard drive failures on the variety of PC based systems that I > get asked to fix. The DOS based units with the Disk-On-Chip modules are > very good and I have never had any problems with them. I have seen a > variety of methods of mounting HDD to try and eliminate the problems > with vibration. One company used to mount the HDD with a spring in each > corner and suspend the HDD like a spider in a web. So……… I would like to > go the solid state route.
> But if the number of read/write times is limited, possibly this isn’t > the best route to follow. If the flash has a wear-leveling scheme that remaps the heavily-written sectors to new locations periodically, then the wear is a much less serious problem. Still, a system that rewrites the home block every minute, for instance, could wear the flash out in as little as 10 days without wear levelling, or in a couple months with it. If you buy top-line (Maxtor, Western Digital, etc.) hard drives that are not the latest-greatest capacity, in other words stable mature technology, and if you keep them cool and don't rattle them, they can last 10+ years. I think the spring suspension is likely to be a good idea. Temperature is also important, and many drives cook along at 50 C in PCs, which can't be good for them. Yes, I would like to see affordable, reliable solid state disks that didn't have some of these problems. Probably, it would be possible to modify one of the existing Linux file systems to take best advantage of a flash disk. If you could mount a flash drive read-only, that would stop all writes to the drive, which would fix the wear problem. Linux will run with the entire boot file system mounted read-only, as I understand it. It can also run with a heck of a lot of the rest of the traditional OS files moved to a read-only file system. All of <anything>/bin/<anything>, and the same for /lib, /etc and some other stuff. This would reduce the amount of space needed on a R-W file system, and that could be on easily accessible USB drives that are simply replaced if they wear out, and copied easily for backup purposes. Jon ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
