>>From: [EMAIL PROTECTED] (Chris Cowan)
>>
>> Anyway, the total transfer time of this process is rather important.
>> (We're talking about a process that presently takes over 10 hours!)
>> I've suggested using "find ... | cpio" or "tar -cvf- ... | (cd ....;
>> tar -xvf-) in order to inject some buffering. (I used both the
>> "stock" OS and GNU versions of these utilities). However, I'm smart
>> enough to know that other NFS and AFS factors come into play here.
I have seen something sort of similiar with AFS.
In our local AFS cell, I have a bunch of files stored in multi-level
directories. I wanted to get a listing of all the files so I did
a command like this:
ls -ld * */* */*/*
Think about how this works. The shell expands the wildcards first.
We can assume that it all fits within the limit for the size of a
command line. So the shell must read all of the directories and every
ACL must be processed. Then the ls program itself
runs and it must search down a directory path for each file. Once
again, every ACL must be processed to go down a directory path.
This sort of thing is really slow in AFS. I can do the same sort of
operation directly on my SUN hard disk and it takes only a small
fraction of the time.
So the bottom line is: Try to avoid a situation where a lot of
directories in AFS must be searched. It can take a long time to
process all of the ACL's.
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[ Joe Ramus NERSC Livermore (510) 423-8917 [EMAIL PROTECTED] ]
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