60 karma · joined October 8, 2010
[1]http://www.cs.toronto.edu/~bianca/papers/sigmetrics09.pdf [2]http://louwrentius.com/please-use-zfs-with-ecc-memory.html
There is a provision in most file systems to use links (symlinks, hardlinks, etc.). Links can cause cycles in the file tree, which would result in a traversal algorithm going into an infinite loop. To prevent this from happening, we ignore links in the file tree during traversal. We note that the algorithms we propose in the paper will duplicate effort proportional to the number of hardlinks. However, in real world production systems, such as in LANL (and others), for simplicity, the parallel filesystems are generally not POSIX compliant, that is, they do not use hard links, inodes, and symlinks. So, our assumption holds.
The reason this cp took such large amounts of time was the desire to preserve hardlinks and the resize of the hashtable used to track the device and inode of the source and destination files.
[0] https://wiki.archlinux.org/index.php/xrandr#Using_xrandr_wit...
"Looking at the top repo for each language also exposes a weakness in the methodology: GitHub’s language identification isn’t perfect and there are number of polyglot projects. The top Java repo is Storm, which uses enough Clojure (20.1% by GitHub’s measure) to make this identification questionable when you take into account Clojure’s conciseness over Java’s."
Too much publicity?
Embracing the distributed approach and realizing the cutoff point leads to building better tools for collaboration and integrating them into the work environment. Without this recognition, the mentality is that you can always talk to someone in person.
I've worked in multinational companies where collaborating with someone across continents, bar the time difference, was just as easy as working with someone down the hall. I currently work for a company that has not yet achieved this recognition, so working with anyone outside my immediate office takes hard work and determination.
irb(main):001:0> hash={:"symbol with space" => nil}
=> {:"symbol with space"=>nil}
irb(main):002:0> hash={"symbol with space": nil}
SyntaxError: (irb):2: syntax error, unexpected ':', expecting tASSOC
hash={"symbol with space": nil}
^
from /usr/bin/irb1.9.1:12:in `<main>'
irb(main):003:0> hash={"symbolwithoutspace": nil}
SyntaxError: (irb):3: syntax error, unexpected ':', expecting tASSOC
hash={"symbolwithoutspace": nil}
^
from /usr/bin/irb1.9.1:12:in `<main>'
irb(main):004:0> hash={symbolwithoutspace: nil}
=> {:symbolwithoutspace=>nil}
irb(main):005:0> hash={symbol with space: nil}
SyntaxError: (irb):5: syntax error, unexpected tIDENTIFIER, expecting keyword_do or '{' or '('
hash={symbol with space: nil}