Berkeley CSUA MOTD:Entry 38233
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2025/05/25 [General] UID:1000 Activity:popular
5/25    

2005/6/21-25 [Computer/SW/Unix] UID:38233 Activity:nil
6/21    What's the currently accepted "best" fastest way to write a lot of
        little data to a file in Unix? Is it still mmap/memcpy, or is there
        something more advanced nowadays? Maybe send me e-mail? -- Marco
        \_ I'm curious as well, so please post responses here.  --darin
        \_ I think you will find that it depends entirely on the hardware
           platform and in most cases the programming style only affects
           a few percent on the fastest RAID drive arrays.  this is because
           RAM and CPU are so much faster than disks.  trying to do high
           bandwidth network I/O, on the other hand can be tricky and
           interesting if you are into that sort of thing... zero-copy
           asynchronous bulk I/O.
           \- i agree, a lot of little details matter. is it totally
              concurrency domainated, what kind of device is being
              written to, is it ok to write to cache or do you need
              to flush to metal, can you use some hack like immediate data
              [veritas], is locking an issue? does your application only
              use traditional sematics [supercomputing uses have special
              ways of doing large i/o], can you choose your file system,
              is byte range locking an issue? is the rate at which you
              are given inodes an issue? etc. it would be interesting to
              see how IBM/GPFS would do at this.
2025/05/25 [General] UID:1000 Activity:popular
5/25    

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