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April 23, 2004

Working on bladecenters.

Currently playing a lot with IBM's xSeries blade centers, very cool. I'm running RHAS 2.1 on them and our internal drivers for the next WebSphere etc, doing performance work, proof of concepts etc.

I have them setup pretty simply, I'm using a SAN/NAS box for DASD over iSCSI which works incredibly well over gb ethernet. Running DB2 at 3k tps over iSCSI on a test yesterday using a software iSCSI initiator. Still showing 59mb/sec between the DB2 box and the SAN using iSCSI at 12k io/sec. Pretty awesome for commodity hardware like blades and gb ethernet, no fiber etc. Matches the economics of blades better than fiber channel.

I just got ssh working between the blades and just wanted to do a quick post showing how to set it up.

Basically, run the following command on each machine

ssh -t rsa -N ""

This generates a key pair in your home directory. Copy the pub key to a shared NFS volume. Do this on each machine.

Now, on one machine, in the shared volume, cat all the public keys together using:

cat *.pub > authorized_keys

Now, copy this file to each machine in the ~/.ssh directory for the user using the following command:

scp authorized_keys carreral1:~/.ssh

where carreral1 is your host name. You'll have to enter your password for each server. Remember to also do it for your current machine.

Once the authorized_keys file is in the directory then ssh, scp etc will work without entering the password. This makes using the blade center pretty convenient in a test environment.

I'm using putty as my ssh client on windows. Works pretty well.

I'm currently using NIS for user id and groups etc. I wired the NAS to use NIS also. To avoid a spof, I made one blade the NIS master and all the others NIS clients. The clients keep a copy of the NIS database and hence keep working if the NIS master server fails.

Currently, working to use IBM director, PIXIE etc to make installing the blades easier, switching OS etc on the fly and using the iscsi-init project on source forge to boot the blades from iSCSI volumes rather than local DASD.

April 23, 2004 in Web/Tech | Permalink

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