11-17-2014
Quote:
Originally Posted by
kogorman3
Defragged? I'm not sure how to do that on Linux, so I am using a fresh 2-TB drive formatted ext4 and directing sort to use it for temporaries. It's otherwise empty.
ext4 partitions are relatively easy to defrag, being designed with runtime defragmentation in mind (yes, runtime -- no need to unmount) via the e4defrag utility. There's no point defragging an empty partition, but check that your input and output partitions aren't a mess after all this testing.
Quote:
I've got 32 GB RAM and a 64-bit CPU. That's big enough for the whole test file, but the parameters to sort don't let it work that way.
The process of merge-sorting doesn't work that way. No matter how big your buffers are, it has to do the same number of merges on the same number of elements of the same sizes, nearly all of them tiny... Starting with billions of 2-element merges, half the number of 4-element merges, etc, etc, etc. (A little oversimplification, but the merging options don't substantially change this.) That's why pushing buffers to ridiculous sizes is so little help -- they're nearly always dead weight except for the final merge, when it's never going to be big enough to matter anyway.
Last edited by Corona688; 11-17-2014 at 11:17 AM..
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LEARN ABOUT CENTOS
git-merge-index
GIT-MERGE-INDEX(1) Git Manual GIT-MERGE-INDEX(1)
NAME
git-merge-index - Run a merge for files needing merging
SYNOPSIS
git merge-index [-o] [-q] <merge-program> (-a | [--] <file>*)
DESCRIPTION
This looks up the <file>(s) in the index and, if there are any merge entries, passes the SHA-1 hash for those files as arguments 1, 2, 3
(empty argument if no file), and <file> as argument 4. File modes for the three files are passed as arguments 5, 6 and 7.
OPTIONS
--
Do not interpret any more arguments as options.
-a
Run merge against all files in the index that need merging.
-o
Instead of stopping at the first failed merge, do all of them in one shot - continue with merging even when previous merges returned
errors, and only return the error code after all the merges.
-q
Do not complain about a failed merge program (a merge program failure usually indicates conflicts during the merge). This is for
porcelains which might want to emit custom messages.
If git merge-index is called with multiple <file>s (or -a) then it processes them in turn only stopping if merge returns a non-zero exit
code.
Typically this is run with a script calling Git's imitation of the merge command from the RCS package.
A sample script called git merge-one-file is included in the distribution.
ALERT ALERT ALERT! The Git "merge object order" is different from the RCS merge program merge object order. In the above ordering, the
original is first. But the argument order to the 3-way merge program merge is to have the original in the middle. Don't ask me why.
Examples:
torvalds@ppc970:~/merge-test> git merge-index cat MM
This is MM from the original tree. # original
This is modified MM in the branch A. # merge1
This is modified MM in the branch B. # merge2
This is modified MM in the branch B. # current contents
or
torvalds@ppc970:~/merge-test> git merge-index cat AA MM
cat: : No such file or directory
This is added AA in the branch A.
This is added AA in the branch B.
This is added AA in the branch B.
fatal: merge program failed
where the latter example shows how git merge-index will stop trying to merge once anything has returned an error (i.e., cat returned an
error for the AA file, because it didn't exist in the original, and thus git merge-index didn't even try to merge the MM thing).
GIT
Part of the git(1) suite
Git 1.8.3.1 06/10/2014 GIT-MERGE-INDEX(1)