After System Crash - Can't Boot to External FW Drive

[DonP]

On an early 2009 24" iMac, part of my backup strategy is weekly SuperDuper backups to an external Firewire drive. The FW drive has always been a bootup option if I hold the "option" key when booting and I could run from the FW drive no problem.

Well yesterday I had a system crash and was unable to boot to the iMac internal HD, and the FW drive was not visible when booting. I suspected a hardware failure but surprising was able to restore from a Time Machine backup (14 hours). After restore from TM I was again able to boot to the internal HD and the FW drive was visible again.

So obviously my FW backup strategy failed, but why would a system crash make the external FW drive unavailable? Is that expected behavior if I lose the internal HD in the future? Should I not plan to boot to the FW drive if the internal HD fails?

 

[nambuccaheadsau]

Time will tell I guess.

Maybe the internal drive is failing or something more serious like a logic board. Whilst it runs fingers crossed. Like me, itn is showing its age maybe.

 

[Fishrrman]

After your weekly cloned backup, might be worth taking a few minutes to actually BOOT from the backup, just to test it out.

 

[DonP]

I was able to get the external FW drive to boot by having the drive spinning during the "option" key boot up sequence. So I'm up and running for now, with a 1T HD coming in from macsales. That will keep me going until new iMacs are available later this year. Thanks for the advice guys.