Re: PCIe flash device for cdimage.debian.org?
On Sun, 31 Mar 2013, Steve McIntyre wrote:
On Sun, Mar 31, 2013 at 03:58:44PM +0900, Hideki Yamane wrote:
Thanks for your comment about PCIe flash device usage on https://dudle.inf.tu-dresden.de/o87yji5j/
Anything that's compile intensive / something like cdimage.debian.org
that is serving large files and may be IO bound / the package search
engine for Debian since that takes a lot of memory and would be heavily used.
You mean, building cdimage on cdimage.debian.org, or serving cdimage
on that? If it can reduce much build time, it is worth to try, IMO.
Actually, that's a really good idea. CD builds are *very* IO-heavy and
involve lots of random-access and small reads and writes. SSD would be
a nice fit if we can get something large enough - we need to keep a
local mirror and the temporary build trees in a single
filesystem. Currently we're using ~900GB of a 2TB filesystem.
I would add that for serving cdimage.d.o to the public/other mirrors a
really fast SSD is rather far from what we need. The biggest current need
there is a replacement of the backend storage that is starting to see
stability issues, and what would fit in there best is half a rack to a
rack of SATA JBOD drawers with SAS or FCAL uplinks.
The caching frontends could, in theory, get a bit faster with a set of
SSDs, but curently we don't really have much problems in saturating as
much as we are allowed to of the whole university's 10Gbit uplink using
spinning disks. See http://ftp.acc.umu.se/about/ for the architecutre of
the cluster that handles the public-facing parts of cdimage.d.o.