[Beowulf] Doing i/o at a small cluster

[Andrew Holway]

2012/8/17 Vincent Diepeveen <diep at xs4all.nl>:
> The homepage looks very commercial and they have a free trial on it.
> You refer to the free trial?

http://nexentastor.org/ - Sorry wrong link. Its a commercially backed
open source project.

> Means buy raid controller. That's extra cost. That depends upon what
> it costs.

You just need to attach the disks to some SATA port. ZFS does all the
raid stuff internally in software.

> But it does mean that every node and every diskread and write you do,
> that they all hammer at the same time at that single basket.

ZFS seems to handle this kind of stuff elegantly. As with hardware
raid each disk can be accessed individually. NFSoRDMA would ensure
speedy access times.

>
> I don't see how you can get out of 1 cheap box good performance like
> that.

Try it and see. It would certainly be much less of a headache than
some kind of distributed filesystem which, in my opinion is complete
overkill for a 4 node cluster. All of the admins that I know that look
after these systems have the haunted look of a village elder that must
choose which of the villages daughters must be fed to the lustre
monster every 6 months.

Dont forget to put in as much memory as you can afford and ideally an
SSD For read cache (assuming that you access the same blocks over and
over in some fashion)