For a lot of the sort of utility programs I write in Python, the onlything the program can really do when it runs into an operating systemlevel error is report whatever the problem is and exit. So programsstart out as one big try:/except: block:

try:    fp1 = open(fnameA, "r")    ....    fp2 = open(fnameB, "r")    ....except EnvironmentError, e:    die("OS error: %s"

If you swap an Ubuntu 6.06 system disk between hardware units (evennominally identical hardware units, like from one Dell 2950 to anotherPE2950), the system will come up scrambled Ethernet devices and youwon't be on the network. (As we found out the hard way today.)

This happens because the only way Ethernet devices get consistentnumbers on Ubuntu machines is because Ubuntu remembers the mappingbetween hardware ethernet addresses and the ethN name that they shouldget.

This month, someone came to the local Unix group with an issue: they were using a CGIprogram to kick off a background process, but when they visited theCGI's URL in their web browser their browser just sat there, spinningthe little 'I am fetching the page' throbber. After the dust hadsettled and the right advice had been given (the background processneeded to have its standard input, standard output, and standard errorredirected to /dev/null ), I got to thinking about

It is possible to get a DiskSuite metadb replica into a sufficientlydamaged state that it will panic the system in early boot, whichis especially irritating when you aren't using it for anything . This can lead to you needing to clear metadbreplicas.

(If you get past boot by turning off svc:/system/metainit thesystem panics when you run metadb or metainit , which is nottoo helpful for actually dealing with the problem.)

If you don't care about leaving the actual bits intact for