Install, NFS and Shared Keys  //  Tuesday, September 9, 2008

Good evening, ladies and gentlemen. I have made more progress on the Grid, and I believe I am formulating a valid methodology on how to actually deploy the machines once I've figured everything out. I'll cover that at the end, but first, here's what happened today:

I began the night by doing some compare and contrast of LVM vs standard partition schemes, and also did some reading on the differences between ReiserFS, XFS, JFS and EXT3. I decided on LVM and EXt3. LVM offers the ability to dynamically resize my partitions, which could come in handy should I ever (however unlikely) run out of disk space on the existing partition. It also allows me to do VG snapshots on the filesystem as it is running, without taking anything down. That will make for useful backups on-the-fly. I chose EXT3 because it is the most stable and widely-supported filesystem for Linux.

In order to test this setup, I moved a second box into the lab, and stacked it right on top of the first. Secondly, I configured DNS for both systems' static IPs and applied the settings in /etc/network/interfaces. I'll spare you the details, because if you've seen one, you've seen them all. I've kept disseminate, dubbing the second system mete.

Second, I configured /etc/hosts to include the gridN hostnames, and a few necessary system hosts. This I will post, obfuscating IPs as I see fit.

# Me localhost disseminate

# Grid hosts
10.XX.XX.1 grid1 nfs-host
10.XX.XX.2 grid2

# Necessary System Information
10.NN.NN.1 xdc1 ntp-host

# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts
I didn't touch any of the IPv6 stuff that comes with Ubuntu, both because we don't use it, and because I haven't bothered to learn anything about IPv6 yet (the latter very well may be a symptom of the former). This file was taken from disseminate, but is essentially the same as the one from mete.

I cron'ed the clock to update automatically at midnight against the campus-wide ntp server. Also, for development purposes, I have set up disseminate/grid1 as the system NFS host. Because of this, and although I will eventually be setting up both in tandem, grid2 will be the system whose image is distributed to the other machines.

That said, I blew away the /home directory on mete/grid2, and exported /home on disseminate/grid1 via NFS. Mete's /etc/fstab was modified to mount appropriately on boot. The effect was splendid. Here is the entry in disseminate's /etc/exports:

/home 10.XX.XX.0/24(rw,sync,no_subtree_check,no_root_squash)

This will allow all systems on the Grid's VLAN to mount /home, and will allow root to be all rootlike if it wants to.

Here is mete's /etc/fstab entry for /home:
nfs-host:/home /home nfs rw,suid 0 0

As trivial as it is, I will not discuss how I went about setting up SSH Shared Keys. I'm sure a simple Google search could turn up much more useful tidbits than I wish to divulge here.

For coming posts, look forward to how I am going to do cross-system credential sharing (or whatever the technical jargon for that is). I really like LDAP, but I feel like my supervisor would frown on such a complex solution. Also, I will begin tackling the MPICH2 install problem.

Here's to sleep,


posted by Christian @ 7:46 PM

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