Hi, Building on some data produced earlier I've run a "more scientific" test of determining the exact overhead of ubifs on XO-1, over jffs2.
I build 2 OS images from the same package set, one using jffs2, and one using the jffs2 boot / ubifs root setup used in development builds. I installed the ubifs one on an XO-1, copied over a 50mb binary file as many times as I could into /root, and counted the total amount of data written before hitting disk full. Then I did the same test (same 50mb file) on the same laptop but using the jffs2 image. Results are: ubifs: I could write 309mb jffs2: I could write 382mb 382-309 = 73 However, the ubifs layout includes a 24mb jffs2 boot partition which must be excluded for the purpose of calculating the overhead of the filesystem switch. 73-24=49mb (this calculation loses a bit of accuracy as with compressed filesystems you can often store more than 24mb of data in 24mb of disk space, but as we're only talking 24mb this calculation can only be a few mb "wrong" at the most) Conclusion: the overhead of using ubifs instead of jffs2 on XO-1 is around 50mb (That ignores the additional overhead through our choice of partitioned layout and duplication boot partition contents on root too, and focuses exclusively on the overhead caused by the fs switch alone) Daniel _______________________________________________ Devel mailing list [email protected] http://lists.laptop.org/listinfo/devel
