What Illumos/OmniOS PCI device names seem to mean
When working on an OmniOS system, under normal circumstances you'lluse friendly device names from /dev and things like dladm (fornetwork devices). However, Illumos-based systems have an underlyinghardware based naming scheme (exposed in /devices ), and undersome circumstances you can wind updealing with it. When you do, you'll be confronted with relativelyopaque names like ' /pci@0,0/pci8086,e04@2/pci808
How to get Unbound to selectively add or override DNS records
Suppose, not entirely hypothetically, that you're using Unbound andyou have a situation where you want to shim some local informationinto the normal DNS data (either adding records that don't existnaturally or overriding some that do). You don't want to totallyoverwrite a zone, just add some things. The good news is that Unboundcan actually do this, and in a relatively straightforward way(unlike, say, Bind, where if this is possible at all it's notobvious)
A brief review of the HP three button USB optical mouse
The short background is that I'm strongly attached to real three button mice (mice where the middle mouse button isnot just a scroll wheel), for good reason .This is a slowly increasing problem primarily because my currentthree button mice are all PS/2 miceand PS/2 ports are probably going to be somewhat hard to find onfuture motherboards (and PS/2 to USB converters are finickybeasts ).
One of the very few three button USB mice you can find is a HPmouse (
Today's odd spammer behavior for sender addresses
It's not news that spammers like to forge your own addresses intothe MAIL FROM s of the spam that they're trying to send you; I'veseen this here for some time .On the machine where I have my sinkhole server running, this clearly comesand goes. Some of the time almost all the senders will be trying alegitimate MAIL FROM (often what they seem to be trying to mailto), and other times I won't see any in the logs for weeks.
Why your Apache should have mod_status configured somewhere
Recently, our monitoring system alerted us that our central webserver wasn't responding. I poked it and indeed, it wasn't responding,but when I looked at the server everything seemed okay and the logssaid it was responding to requests (a lot of them, in fact). Thena little bit later monitoring said it was responding again. Thenit wasn't responding. Then my attempt to look at a URL from itworked, but only really slowly.
If you're a long
Why Unix needs a standard way to deal with the file durability problem
One of the reactions to my entry on Unix's file durability problem is the obvious pragmatic one. To wit, that thisisn't really a big problem because you can just look up what youneed to do in practice and do it (possibly with some debate overwhether you still need to fsync() the containing directory tomake new files truly durable or whether that's just superstitionby now). I don't disagree with this pragmatic answer and it'scertainly what you need to
Why I think Let's Encrypt won't be a threat to commercial CAs for now
One of the questions these days is what effects Let's Encrypt and their well publicized free TLScertificates will have on existing commercial CA s. While LE has become a very popular CA and there have been some amusing signs of nervousness from existingCAs, my personal belief is that Let's Encrypt is not going to be athreat to the business of commercial CAs for the medium term, say thenext few years.
One reason I say this is pragmatic past history. LE is not the firstor only free
Unbound illustrates the Unix manpage mistake with its ratelimits documentation
Our departmental recursive nameservers are based on OpenBSD, whichhas recently switched from BIND to Unbound and NSD. As a result ofthis, we've been in the process of setting up a working Unboundconfiguration. In the process of this we ran into an interestingissue.
A relatively current unbound.conf manpage has this to say about(some) ratelimiting options (I'm excerpting here):
- ratelimit:
- Enable ratelimiting of queriessent to the nameserver for performing recursion. If 0,
Unix's file durability problem
The core Unix API is overall a reasonably well put together programmingenvironment, one where you can do what you need and your questions havestraightforward answers. It's not complete by any means and some of thepractical edges are rough as a result of that, but the basics are solid.Well. Most of the basics.
One area where the Unix API really falls down on is the simplequestion of how to make your file writes be durable . Unix will famously hold yourwrites in RAM for an arbitrary length
How I'm trying to do durable disk writes here on Wandering Thoughts
A while back, Wandering Thoughts lost a just posted commentwhen the host went down abruptly and unexpectedly. Fortunately itwas my comment and I was able to recover it, but the whole thingmade me realize that I should be doing better about durable writesin DWiki . Up until that point, my code for writing comments to diskhad basically been ignoring the issue; I opened a new file, I wrotethings, I closed the file, I assumed it was all good. Well, no, youcan'
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