Another day, another Outlook worm. Tell me again why I continue to use Outlook? Not that I ever open unexpected attachments. For that matter, I rarely open expected ones–I think it’s rude. Ever heard of cut and paste? It’s bad enough that I have to keep one resource hog open to read e-mail, so why are you going to make me load another resource hog, like Word or Excel, to read a message where the formatting doesn’t matter?
The last couple of times I received Word attachments that were important, I converted them to PDFs for grins. Would you believe the PDFs were considerably smaller? I was shocked too. Chances are there was a whole lot of revisioning data left in those documents–and it probably included speculative stuff that underlings like me shouldn’t see. Hmm. I guess that’s another selling point for that PDF-printer we whipped up as a proof of concept a couple of weeks ago, isn’t it? I’d better see if I can get that working again. I never did get it printing from the Mac, but seeing as all the decision-makers who’d be using it for security purposes use PCs, that’s no problem.
I spent the day learning a commercial firewall program. (Nope, sorry, won’t tell you which one.) My testbed for this thing will be an old Gateway 2000 box whose factory motherboard was replaced by an Asus SP97 at some point in the past. It’s got 72 megs of RAM. I put in an Intel Etherexpress Pro NIC today. I have another Etherexpress Pro card here that I’m bringing in, so I’ll have dual EEPros in the machine. The firewall has to run under Red Hat, so I started downloading Red Hat 7.2. I learned a neat trick.
First, an old trick. Never download with a web browser. Use the command-line app wget instead. It’s faster. The syntax is really simple: wget url. Example: wget http://www.linuxiso.org/download/rh7.2-i386-disc1.iso
Second trick: Download your ISOs off linuxiso.org. It uses some kind of round-robin approach to try to give you the least busy of several mirrors. It doesn’t always work so well on the first try. The mirror it sent me to first was giving me throughput rates that topped out at 200KB/sec., but frequently dropped as low as 3KB/sec.Usually they stayed in the 15MB/sec range. I cancelled the transfer (ctrl-c) and tried again. I got a mirror that didn’t fluctuate as wildly, but it rarely went above the 20MB/sec. range. I cancelled the transfer again and got a mirror that rarely dropped below 50MB/sec and occasionally spiked as high as 120MB/sec. Much better.
Third trick (the one I learned today): Use wget’s -c option. That allows wget to resume transfers. Yep, you can get the most important functionality of a download manager in a 147K binary. It doesn’t spy on you either. That allowed me to switch mirrors several times without wasting the little bit I’d managed to pull off the slow sites.
Fourth trick: Verify your ISOs after you download them. LinuxISO provides MD5 sums for its wares. Just run md5sum enigma-i386-disc1.iso to get a long 32-character checksum for what you just downloaded. If it doesn’t match the checksum on the site, don’t bother burning it. It might work, but you don’t want some key archive file (like, say, the kernel) to come up corrupt. Even though CD-Rs are dirt cheap these days and high-speed burners make quick work of them, there’s still no point in unnecessarily wasting 99 cents and five minutes on the disc and half an hour on a questionable install.
As for downloading the file in separate pieces like Go!Zilla does, there’s a command-line Linux program called mget that does it, but it doesn’t follow redirection and it doesn’t do FTP except through a proxy server, so I have a hard time recommending it as a general-purpose tool. When it works, it seems to work just fine. You might try mget, but chances are decent you’ll end up falling back on wget.