On December 18, 2014, Michael Torrie wrote: > Back to Dan's question. What is your end goal here? What will the
> PXE-booted workstations be used for? The idea is to have a central location for all software, all the O/S, etc.... The workstation should be fast, although perhaps it doesn't quite need to be SSD fast. The server is booting via it's own SSD, and then has a Raid 5 of Mechanical HDDs (not Mechanical SSDs, which I've never heard of either, and I have no idea how I missed that I wrote that :| ). Each workstation would boot into a full X environment with the NFS root and with a samba share or a separate NFS share for the RAID itself. Once booted, each machine would be an independent workstation that happens to be diskless (except for a couple of machines that have an optical drive, which most would not have). It would have full access to every day apps like LibreOffice, Firefox, Thunderbird, etc... and the goal is to keep the access speed and load times as close as possible to the times they would be if each machine had booted from it's own SSD. As long as Gigabit will work for this, then that's fine. I think I'll use the advice of trying it and then upgrading if necessary. Thanks! --- Dan On Thu, Dec 18, 2014 at 10:03 AM, Levi Pearson <[email protected]> wrote: > On Wed, Dec 17, 2014 at 10:26 PM, Dan Egli <[email protected]> wrote: > > On December 16, 2014, [email protected] wrote: > > > >> i did an experiment a couple years ago where i booted a > > > >> windows machine off an iscsi target connected over gigabit ethernet. > > > >> loading games and regular desktop usage was almost as good as if the > > > >> hard drive was connected to the local system. > > > > > > > > That's actually impressive. I didn't think Gigabit went that fast. I > recall > > reading somewhere that a base rule of thumb when speaking of speeds over > > the network was to take the advertised speed and quarter it to get the > > actual usage speed. 25MB/sec isn't very fast at all these days. Even > > mechanical SSDs frequently read at 150MB/sec and write at 100MB/sec if > the > > benchmarks I've seen are any indication. I may have to do some tests. > > I would bet that the "feel" of running a system over a network drive > vs. a local drive depends a lot more on latency than throughput, and a > lightly loaded gigabit network has pretty nice latency > characteristics. On my current network at work, an ICMP round-trip is > about .2ms, which is only 10x slower than via the loopback interface, > which is about .02ms. Spinning disks have *minimum* seek times in the > same order of magnitude as network RTT, and the disk's onboard cache > will be cold at boot. A network drive is likely to be a SSD, a RAID > array, or at least have a hot cache. So certain access patterns are > probably *faster* via iSCSI on a lightly loaded network than via a > local spinning disk, or at least there's a potential for being faster. > There are plenty of other variables involved, so YMMV. > > --Levi > > /* > PLUG: http://plug.org, #utah on irc.freenode.net > Unsubscribe: http://plug.org/mailman/options/plug > Don't fear the penguin. > */ > /* PLUG: http://plug.org, #utah on irc.freenode.net Unsubscribe: http://plug.org/mailman/options/plug Don't fear the penguin. */
