One of the things that security people always say is that the first stepin doing a decent security analysis is to figure out your threat model . So, what is the threatmodel for website logins, in other words what sort of attacks are youlikely to face that you need to defend against?

My belief is that there are two or maybe three significant threats thesedays:

• phishing, for which the best defense is getting your users out of thehabit of entering their passwords at all; either have them logged on

I wrote up our basic fileserver design plan back in ZFSFileserverDesign , but it is worth explaining why we are lookingat using many pools. In a nutshell:

Given that we sell fixed size chunks of space to people (as the waywe allocate our storage space), we are always going to have a certainnumber of logical pools of storage to manage. The only question iswhether to handle them as separate ZFS pools or to aggregate them intofewer ZFS pools and then administer them as sub-hierarchies using quotas .

Every so often some ex-DNSBL makes the geek news because itsex-operators have gotten tired of people still trying to use it yearsafter it was taken out of service, and to fix this they make theirex-DNSBL return positive answers for every query, thereby blacklistingthe world and insuring that email systems that still use the ex-DNSBLwill bounce everything until they are fixed. Which should happen fast,because people generally notice when they are not getting email.

(Not always, though.)

When

Here is a suddenly burning question: what protectsthe strength of a ssh connection's encryption?

The answer is that the connection encryption is protected only by thestrength of the random numbers chosen for the initial Diffie-Hellmankey exchange that arrangesthe session key. This protection depends on both the server and theclient using strong random numbers; if an attacker can guess the randomnumber for either side, they can immediately recover the session keysimply by acting out that side of the exchange.

The server's host

I've been testing ZFS over iSCSI storage as an NFS server recently,which has caused me to discover a number of interesting things.In the order that I discovered them:

• each ZFS pool has a cache that has a minimum size that it won't shrinkbelow, no matter what the memory pressure is; this is apparently10 MB by default. If you have 2 GB of memory on a Solaris 10U4x86 machine and 132 separate pools, there is not enough

To stereotype, there are two models of operating your storage: longterm storage , where you evolve your storageover time without the users noticing, and run it into the groundstorage , where you just buy the best thing ofthe moment and replace it when it's too outdated. So, what are thetradeoffs between the storage models, or in other words when shouldyou pick one or the other?

My thoughts so far on this is that there are a number of issues:

• what sort of downtimes can

In addition to the stuff in AutomationCosts , there's another problem(or cost) with custom sysadmin tools: they're almost always at leastnot-good software, and sometimes they're outright bad. They pretty muchcan't help but be because of how they're created.

The typical custom tool is written by at most a small group of people(who are often not actively practicing programmers), is not looked overby very many people, and on top of that is often written

In the old days of V7 Unix, directories weren't quite files butthey were close enough that you could open and read() themdirectly, and they had a simple enough structure that there was nolibrary routine to parse their contents; programs like the V7 ls just did itthemselves. A good part of the reason for this was that filenames wereshort (14 characters max), so directory entries could be fixed-sizedobjects.

In 4BSD, Berkeley expanded the maximum length of

One of the useful things about interpreted languages like Python forprogramming, especially system administration, is that there is nodistinction between the source code and the executable program. Thismeans that you never have to play the exciting game of 'where's thesource, and for that matter the build instructions, and does it evenbuild with a modern compiler?'

(I once had the interesting assignment of converting a program writtenfor the V6 Unix version of C into something that would compile on a moreconventional C