Automated CARP/HAST Failover

Earlier I discussed using HAST to mirror a ZFS across two machines.  I also discussed using devd with CARP interfaces, to run a script when a machine changes between master and backup.  Now let’s glue these together to synchronize a ZFS switch with CARP state, and to run scripts when the system becomes the master or the backup. Continue reading “Automated CARP/HAST Failover”

Proposal accepted for NYCBSDCon

NYCBSDCon accepted my talk proposal:

BSD Needs Books

If you wander into any bookstore, brick or virtual, you’ll see books on Linux, Solaris, Macintosh, and even non-Unix-like operating systems.  The BSD books are far between.  We as a community need to address this if we’re to expand our reach.

This talk covers designing, selling, writing, and promoting your own technical book, with a special emphasis on BSD books.  I’ll cover everything that I wished I’d known before I started, common errors, where the “generally accepted wisdom” is wrong, how to actually complete the book, how you can use your publisher to your advantage, post-publication work, and — most important — how to enjoy the process.

I’ve attended NYCBSDCon repeatedly, and have never been disappointed.  They always have interesting content and the after-hours events are fabulous.  (Yes, I like BSDCan as well, but there is no place in the world like New York City.)

Now to figure out how I do what I do…

CARP and devd on FreeBSD

In my last post I discussed using HAST with ZFS.  That tells you how to replicate a filesystem back and forth between two machines.  That’s nice, as far as it goes, but I want automatic failover.  Clustering.  I want to wake up in the morning to a message that says “machine 1 failed, machine 2 took over, and nobody noticed” instead of a lot of messages from angry customers.  The standard FreeBSD failover mechanism is CARP, the Common Access Redundancy Protocol.  Here’s the basics of CARP. Continue reading “CARP and devd on FreeBSD”


There’s a nice tutorial on using HAST (Highly Available STorage) with UFS and ucarp.  That’s very nice, but in my failover scenario I can’t use UFS; a fsck would take too long, and a background fsck would be most likely to lose the data I’m most likely to need.  And FreeBSD comes with a kernel-side CARP implementation; why would I use the userland implementation instead?  So: the tutorial is great, except it doesn’t do what I want.  I’ll attack this problem in two phases:  one, get HAST with ZFS running, and experiment with it.  Two, get CARP failover to trigger HAST failover automatically.  (I believe I can use devd for CARP-initiated failover, but I’ll need to do further research on that.  That’ll be another posting.)  Today I’m experimenting with HAST and ZFS.  Continue reading “HAST and ZFS”

iSCSI boot FreeBSD?

Daisuke Aoyama (Google translation) has created a kernel module to glue an iSCSI disk to a boot drive. While the driver was intended for use with iBFT, you can also use it with gpxeboot.  He has even made FreeBSD install ISOs with iSCSI support available.  The server has limited bandwidth, so start the download well before you want to use it.  (I have previously looked at using iSCSI disks on FreeBSD.)

Thank you, Aoyama-san!

Uninstalling Windows 7 Games, with Prejudice

I’m making an effort to work in the same way as my co-workers.  This means using a Windows laptop, after fifteen years of Unixish desktops.  I like to change desktop operating systems every couple of years anyway, so this isn’t a huge deal.  The new work laptop came with Windows Vista, HP Bastardized Overloaded Nagware Edition, so the company Supreme Leader got me a Windows 7 DVD and license.  I threw the disk into the laptop, kept hitting ENTER until the OS was installed, fed it my license key, and was up and running.  That almost destroyed my productivity forever.

Continue reading “Uninstalling Windows 7 Games, with Prejudice”

first two reviews of Network Flow Analysis

In the time between when a book is released and when the first reviews appear, authors experience a variety of symptoms ranging from unease to outright panic.  “Did I miss something obvious?”  “Did I really screw up?”  “Am I the laughingstock of the tech industry?”  Web pages can be fixed, but printed books are immutable; any errors are immortalized.  Over the years, I’ve gotten the symptoms down to an ongoing gentle nausea.

Thankfully, the first two reviews on Network Flow Analysis are out.

I sent Justin at DragonFly BSD Digest a review copy of NFA, and he not only read the book, he’s planning to implement it at work.  I’d call that a thumbs up.

Then there’s a review from Dad of Divas.  DofD reviews lots of stuff on his blog, mostly stuff that he receives as a promotion.  The odd thing is, I have no idea how he got a copy of the book.  The lesson?  The publishing publicity machine is mysterious and inexplicable, even to those of us trapped inside it.

But, having read the reviews, my lingering dread and nausea is gone.  Thanks, folks.