Author: Cody

Posted on

“You cannot install Mac OS X on this volume. You cannot start your computer from this volume.”

Installing OS X 10.3 tonight and ran into this problem. I was installing to a 30Gb disk that used to have a copy of slackware on it so when I ran the installer I had to run the disk utility and erase the old disk. Once I resumed the install I received the error message:

“You cannot install Mac OS X on this volume. You cannot start your computer from this volume.”

After scratching my head for several minutes and re-trying the disk utility a couple times I decided that maybe it simply needed a reboot. Sure enough a reboot using the 10.3 install CD’s cured the problem. I hate non-descript errors, if a piece of software is not going to perform a function due to a problem it should tell you WHY. Anyway, easy enough fix.

EDIT Oct 26 2008: I experienced this issue again tonight while configuring a software raid on a G4 Tiger machine. After the raid was initialized I simply rebooted the machine and entered setup again, the installer allowed me to install on the raid partition after that.

Posted on

Debian on my Sun Ultra 5

After playing with Solaris 10 for a few months I decided to try one of the linux-SPARC64 ports on my little ultra5.

My Sun Ultra 5

It’s a decent little box with an Ultra Sparc IIi @ 400Mhz and 512mb ram but one thing it lacks that I wish it had was SCSI. Sun used IDE in the Ultra5/10 to make it’s price point as low as possible. Unfortunately their choice of IDE controller chips wasn’t the greatest and the disk I/O performance on the ultra5 is terrible. Perhaps that was a strategic move on Sun’s part to ensure the Ultra 5/10 didn’t undercut sales of it’s much more expensive workstations and servers. And of course, Sun being Sun you can’t just use any old PCI SCSI card, you need one with Sun boot code support which immediately makes the price 2-3x the going rate for a decent SCSI card. Anyway, all that aside it’s a cheap little machine to learn the quirks of Sparc64 on.

Solaris is nice to know but truly a pain in the butt to work with compared to Linux if you want to build GPL software. I tried FreeBSD sparc64 but found the port a little unstable. I don’t know if it’s the age of the platform or the fact that anyone that wants to run Sun hardware is likely to be running Solaris but most distro’s that used to support Sparc have either gone away or stopped releasing sparc builds. Thankfully debian still has a well maintained sparc port that seems to be running fine on my little Ultra5.

There are a few quirks like the local console (keyboard/mouse) doesn’t appear to work, the console on serialA works fine though. I’m currently using my Ultra5 for backups with rsync, a music server running gnump3d and a secondary DNS caching box for my network. Soon it will be running a Hylafax fax server and Nagios monitoring. If I can find a Sun SCSI card cheap enough on ebay I will be running my DAT tape drive on it as well. Not bad for a machine that cost $100 used two years ago.

Update Nov 2007: This little machine made the trip across the country with me and is currently my webserver. If you’re reading this you’ve used CPU cycles on my ultra5! 🙂

Posted on

What is it about Friday afternoons anyway?

Today at 3:35pm a couple of critical servers went off line at the datacenter with no warning or explanation. Of course this has to happen at the end of the day on a Friday! After 5 seconds of bewilderment I called the NOC and had someone head out to the cage to take a look at what was going on. One of our power strips just decided to shut off without warning. Most boxes just generated alerts about loosing a power supply but 2 machines were older and did not have dual power supplies so they simply went offline. We moved these boxes over to another power strip and waited for the facilities guys to come and diagnose the problem.

After removing the power strip’s locking plug from under the raised tiles and testing the power source they determined that the issue was local to the power strip. Upon plugging it back in the power strip started working again. The power eng figured that the new power deviation we had installed last week may have knocked the plug loose so we left the power strip in place and decided to wait.

An hour later again the circuit went down. This time our NOC people decided to replace the troubled power strip and now everything appears stable. Flakey power makes me nervous, especially in a mission critical environment.

Posted on

Dell 6850 power requirements

We recently updated some lagging DB servers to new hardware. We installed some new Dell 6850 quad processor machines with 8GB ram, internal Perc raid mirror and external PowerVault 2200s storage. The hardware provisioning went fine with the exception of one odd matter, Dell PowerEdge 6850’s only run on 220volt AC!

All our existing PDU’s were 20 amp 110v and running at 70% utilization so even if the the servers worked on 110 they would put us over capacity. I just thought it was odd that the servers only ran on 220 when their non-rackmount counterparts, the 6800’s run on either 110 or 220. Dell says it’s due to space constraints on the new 6850’s, they don’t have the room to have a larger power supply.

Anyway, if you’re ordering 6850’s make sure you get dell to include a 16 amp 220v PDU and the proper power cables. Thanks to the quick response time of the guys at Savvis we had our power divation installed in 3 days, which made my life a lot easier.

As a side note, if you’re building a DB server that needs to really haul you should spend some serious time evaluating the fastest possible I/O configuration for your budget. Moving from raid5 to raid 1+0 and separating innodb storage from binlogs and temp tables has made our MySQL server at least 2-3 X faster.

Posted on

Portupgrades gone wrong…

In a blaze of stupidity I missed the courier-imap config files in my backup script so tonight when upgrading said package I managed to destroy pop3 access to the entire mail server. Nice one. Anyway, things should be back to normal shortly, rewriting the configs as we speak. I guess that’s what I get for wanting to upgrade software that was working perfectly to begin with.