One of the things that irritate me about ZFS is the interactionbetween snapshots and quotas, specifically that ZFS snapshots countagainst a filesystem's quota. I can only call this robot logic ; it is in a sense completely correct and itprobably simplifies the implementation, but it is not useful .

The problem is that snapshots are a system level thing; having themcount against user quotas is a problem waiting to happen. Considertrying to explain to a user that they have 'run out' of disk spacebecause the

It amuses me how Amazon's EC2 and S3 services are a clever return to theera of timeshared mainframe computing. Not in what is being directlysupplied, but in its economics. Rather than the fixed monthly pricecommon these days, EC2 and S3 charge you a usage based fee for bothstorage and CPU, just as timesharing computing used to.

(Of course, some segments of timesharing computing used to charge youfor anything that moved and they could measure. And did so with ratesmuch

Here is an important corollary to KillOrderImportance : when your systemis overloaded, you should always kill processes with ' kill -9 ' .

There are a fair number of sources that will tell you that you shouldalways kill processes with something besides kill -9 , unless theywon't die from lesser measures. In an overloaded situation this isterribly wrong: either the processes don't have a signal handler for thelesser signal, in which case the two are equivalent, or they do have asignal handler,