When you have fileservers, they naturally become the center of the world
Every so often I spend a little bit of time thinking about how wemight make some use of cloud computing, generally without comingup with anything meaningful, and then inevitably I wind up thinkingabout what makes it hard for us. So today I want to mention a littledownside of having fileservers ,which is that once you have fileservers they can easily become thecenter of your computing universe and then everything becomes tiedto the fileservers.
To make this concrete, let's look at IMAP. When you build an
I continue to have strong confidence in ZFS On Linux
Three years ago I wrote about my experiences with ZFS on Linux up to that point, which involved a few monthsof running it on my office workstation. Given that we're probablygoing to use it for our new fileservers ,I feel it's a good time to give an update with my experiences andviews. The short version is that I've had a pretty great time with ZFS On Linux , without any particularlysignificant problems, and my experiences with it have given me apretty strong confidence in
There were Unix machines with real DirectColor graphics hardware
As I mentioned yesterday , one of thequestions I wound up with was whether there ever was any Unixgraphics hardware that actually used X11's unusual DirectColor mode.Contrary to what you might expect from its name, DirectColor is anindirect color mode, but one where the the red, green, and blueparts of a pixel's colour value index separate color maps.
The short version of the answer is yes. Based on picking through the X11R6 source code , therewere at
The interestingly different display colour models of X10 and X11
A while back I wrote about what X11's TrueColor means . In comments Aristotle Pagaltzis and I wound up getting into the fun worldof X11 visual types , especiallythe DirectColor visual type, which has an indexed colormap likePseudoColor but with the R, G, and B channels indexed separately.As a result of this I wound up with two questions: where didDirectColor come from, and was there ever any hardware that actuallyhad real DirectColor support? Today I'm mostly going to tackle
Our next generation of fileservers will not be based on Illumos
Our current generation of ZFS NFS fileservers are based on OmniOS. We've slowly been working on the design of ournext generation for the past few months, and one of the decisionswe've made is that unless something really unusual happens, we won'tbe using any form of Illumos as the base operating system. While we'regoing to continue using ZFS, we'll be basing our fileservers on either ZFS on Linux or FreeBSD (preferably ZoL,because we already run lots of Linux machines
Our next generation of fileservers will not use any sort of SAN
We've been using SAN-based fileservers here for a long time, partlyfor reasons that I once wrote about in Painless long term storagemanagement without disturbing users .Our current and past generations of ZFS fileservers havebeen based around an iSCSI SAN, and before that we had at least onegeneration of Fibre Channel based fileservers using Solaris (with DiskSuite and relatively inexpensive hardwareRAID-5 boxes. Some of the things we've wanted from a SAN haven'tworked out lately butothers have, and I
Checking RAM DIMM information from inside Linux
Suppose, not entirely hypothetically ,that you have some machines where you don't know exactly what theirDIMMs are and how they're set up, and you'd like to. Obviously youcan find out all of this information if you take the machine down,open it up, and inventory the DIMMs, but fortunately for your uptimeyou can extract a surprisingly large amount of information fromwithin Linux without having to go that far.
If you have a NUMA machine, you can get a bunch of information
I feel that Firefox forks that would be useful to me are doomed
One of people's reactions to the Firefox 57 (Quantum) change inaddon support, as well as recent events ,is to switch to Firefox-based browsers such as Waterfox . I looked briefly at Waterfoxat one point but my gut wasn't happy, so I've sat on it ever since. After themost recent events made me think about it again, I've figured outwhat I feel about it. The summary is that unfortunately, I thinkthat the useful (to me
Attachment types that we see in email from Zen-listed IP addresses
As part of yesterday's entry , Ibroke down what percent of various sorts of attachments we receivedcame from IPs listed in zen.spamhaus.org. Today I'm going to basicallyinvert the question and ask instead what sort of attachment typeswe get sent from Zen-listed IPs. As before, I'm going to be usingthe past nine weeks and a bit of logs, because our weekly logrotation makes it easy to do that.
(Because our attachment type logging comes after our RCPT
What file types we see inside ZIP archives with only a single file in email
Earlier this year, I wrote about how email attachments of a single.zip inside another zip were suspicious ,and then did a file type breakdown for them .Malware is ever-mutating so nested ZIP archives have gone out ofstyle by now, but instead we're seeing a not insignificant amountof attachments that are ZIP archives with only a single file inthem. Today I want to do a breakdown of those file types that we'veseen over the past nine weeks or so.
So here are the