Peter Humphrey <peter <at> humphrey.ukfsn.org> writes:
> My little Atom box's hard disk spins up every minute or so, and watching > iotop I see it's jbd2 that does it. > Google shows that others have similar problems. > Before I re-create all the partitions as reiserfs - and remove ext4 from the > kernel - does anyone have a lighter solution? Well, lots in good responses, so please do not interpret mine as saying it's a better solution that what others are suggestion. Atom is more of an embedded processor than a true workstation/server processor, imho. As such, it it more "bare metal" meaning countless software developments for AMD and Intel processors intended for workstations and servers, are irrelevant, useless, harmful, redundant, or just plain stupid for embedded processors. like the atom. So now you (and I and millions of folks) are trying to use mega-software (linux distro) on a bare-metal processor.... NOBODY has fleshed out these issues on an itemized basis. i.e. the knowledge base is sparse (at best) since the only one that can really do this is the silicon vendors and they have a VESTED INTEREST in not doing so. Furthermore, since Atom and ARM and many other embedded processors are combined as "cores" on an SOC (system on a chip) each revision of such hardware by each vendor can have different addtional hardware on the SOC that a generic compiled software distro is clueless about. That's why numerous devices that attempt low power linux, use a proprietary linux based on montaVista or countlesss other embedded linux vendors. These purveyors and vendors of the various embedded linux offerings do not publish anything about these hardware details for some issues and do include documentation, deep in the specifications of the processor. When you stray from that (the linux distro that come with the product), you are on your own, finding piecemeal information about low level hardware intricacies....ad-nossium.....imho. If the device came with some OS other than a linux hack..... YOu are much futher from paradise then with a default linux distro as the OS the vendor provided. It does not mean you will not be successful, just your journey is perilous, at best, if optimization is what you seek. Long story short, for years I have been building firewalls and embedded linux bridges, sniffers and other passive ethernet based devices, using ext2. Works beautifully with little attention. Not optimized, but avoid a HUGE time-sink. I encounter a myriad of issues, when trying newer file systems for embedded linux systems. Ext-2 works for years on Compact Flash drives if you do not log, or limit logs to an NFS link or such. As one reader suggested, you have to audit, one application at a time, to find the culprit. It's actually a never ending process, imho, as feature creep on a myriad of software packages will usually lead to performance issues and thus more aggressive algorithms on data movement. You may want to try some of the file systems intended for embedded system (as part of the newer linux kernels) and the tuning parameters therein, if you are looking for a robust solution. Also delete what you do not need from the atom based system, just as a general policy. Minimal and embedded are different facets of the same thing. Intel atom is first and foremost an embedded processor, not a CISC processor. I.E. just because it compiles, does not mean it runs well on limited resources or bare metal. Happy Hunting, James
