Dear Okajima:   My considers is below:   Some flash disk is slow, so I would like to compress the read-only filesystem to minus the overhead of reading from flash disk, since my cpu is not always 100% occupied.    And could you suggest how can I test the read only file system. Xavi Kpan
On Thu, Dec 3, 2009 at 1:22 PM, <[1][email protected]> wrote: xavi kpan: > Dear all: > > Â Â We use aufs to mount an ro rootfs(/usr/,/lib/...) and a writable layer > on it. both are ext3. > Â Â The lmbench show that creation of file, deteting of files are only a > half of the speed of the ext3. > Â Â Any suggestion of it? > > Â Â And Since the the rootfs is readonly, could I change it to squashfs to > accelerate the read performance? > > Best Regards > > -- > a fan of Barcelona and Linux Hello xavi, If you expect aufs to enhance the speed of filesystem, maybe you are wrong. Essentially aufs is an overhead of filesystem layers. But I am tyring minimize the overhead and aufs has some configurations for that. Read the aufs manual and configure, specify the options, then you will get the best performance. Squashfs is also an overhead because it decompress the contents of fs. Generally every overhead has its pros and cons. In squashfs, you pay the cpu cycles for decompression, but you get more disk space, for instance. The overhead of aufs is similar. Even I implement the minimum overhead and you configure to minize it, the overhead exists. But you will get some features you need. If those features are less useful than its overhead, then probably you don't need aufs. If you configure aufs and specify some options, the performance will gain, but of cource you will lose some features. J. R. Okajima -- a fan of Barcelona and Linux References 1. mailto:[email protected]
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