David Rosenstrauch skrev:
On 09/14/2011 02:02 PM, Per Steffensen wrote:
Hi
If my goal is to have multiple physical disks seem as one big disk with
redundancy built in, why would I use a HDFS cluster among machines with
one disk each, instead of using software RAID like md(adm) directly on
top of the disks? I am looking for pros and cons on the two solutions.
http://en.wikipedia.org/wiki/RAID#Software-based_RAID
http://en.wikipedia.org/wiki/Mdadm
Regards, Per Steffensen
HDFS was never intended to be a general-purpose file system. It is a
system optimized for a) running map/reduce, and b) holding large
files. It should not be considered as a replacement for RAID.
DR
Thanks for you reply, David. Despite that HDFS wasnt intended to be used
for this, I guess it could be. So if we forget for a moment that it was
not designed/optimized to be used as a general purpose file system
(GPFS), what are the pros and cons for using it as a GPFS with built in
redundancy vs using software RAID. Is HDFS too slow for some kind of
file operations, or what will the problems (and benefits) be? Hope for
some input - I need arguments for and against to be used in a discussion
with a customer. Thanks!
