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Book Review: FreeBSD Mastery: Storage Essentials
Saint Aardvark writes If, like me, you administer FreeBSD systems, you know that (like Linux) there is an embarrassment of riches when it comes to filesystems. GEOM, UFS, soft updates, encryption, disklabels — there is a *lot* going on here. And if, like me, you're coming from the Linux world your experience won't be directly applicable, and you'll be scaling Mount Learning Curve. Even if you *are* familiar with the BSDs, there is a lot to take in. Where do you start? You start here, with Michael W. Lucas' latest book, FreeBSD Mastery: Storage Essentials. You've heard his name before; he's written Sudo Mastery (which I reviewed previously), along with books on PGP/GnuPGP, Cisco Routers and OpenBSD. This book clocks in at 204 pages of goodness, and it's an excellent introduction to managing storage on FreeBSD. From filesystem choice to partition layout to disk encryption, with sidelong glances at ZFS along the way, he does his usual excellent job of laying out the details you need to know without every veering into dry or boring. Keep reading for the rest of Saint Aardvark's review.
FreeBSD Mastery: Storage Essentials
author
Michael W. Lucas
pages
240
publisher
Tilted Windmill Press
rating
9/10
reviewer
Saint Aardvark
ISBN
0692343202
summary
FreeBSD Mastery: Storage Essentials takes you on a deep dive into FreeBSD’s disk management systems.
Do you need to know about GEOM? It's in here: Lucas takes your from "What *is* GEOM, anyway?" (answer: FreeBSD's system of layers for filesytem management) through "How do I set up RAID 10?" through "Here's how to configure things to solve that weird edge-case." Still trying to figure out GUID partitions? I sure was...and then I read Chapter Two. Do you remember disklabels fondly, and wonder whatever happened to them? They're still around, but mainly on embedded systems that still use MBR partitions — so grab this book if you need to deal with them.
The discussion of SMART disk monitoring is one of the best introductions to this subject I've ever read, and should serve *any* sysadmin well, no matter what OS they're dealing with; I plan on keeping it around for reference until we no longer use hard drives. RAID is covered, of course, but so are more complex setups — as well as UFS recovery and repair for when you run into trouble.
Disk encryption gets three chapters (!) full of details on the two methods in FreeBSD, GBDE and GELI. But just as important, Lucas outlines why disk encryption might *not* be the right choice: recovering data can be difficult or impossible, it might get you unwanted attention from adversaries, and it will *not* protect you against, say, an adversary who can put a keylogger on your laptop. If it still make sense to encrypt your hard drive, you'll have the knowledge you need to do the job right.
I said that this covers *almost* everything you need to know, and the big omission here is ZFS. It shows up, but only occasionally and mostly in contrast to other filesystem choices. For example, there's an excellent discussion of why you might want to use FreeBSD's plain UFS filesystem instead of all-singing, all-dancing ZFS. (Answer: modest CPU or RAM, or a need to do things in ways that don't fit in with ZFS, make UFS an excellent choice.) I would have loved to see ZFS covered here — but honestly, that would be a book of its own, and I look forward to seeing one from Lucas someday; when that day comes, it will be a great companion to this book, and I'll have Christmas gifts for all my fellow sysadmins.
One big part of the appeal of this book (and Lucas' writing in general) is that he is clear about the tradeoffs that come with picking one solution over another. He shows you where the sharp edges are, and leaves you well-placed to make the final decision yourself. Whether it's GBDE versus GELI for disk encryption, or what might bite you when enabling soft updates journaling, he makes sure you know what you're getting into. He makes recommendations, but always tells you their limits.
There's also Lucas' usual mastery of writing; well-written explanations with liberal dollops of geek humor that don't distract from the knowledge he's dropping. He's clear, he's thorough, and he's interesting — and that's an amazing thing to say about a book on filesystems.
Finally, the technical review was done by Poul Henning-Kamp; he's a FreeBSD developer who wrote huge parts of the GEOM and GBDE systems mentioned above. That gives me a lot of warm fuzzies about the accuracy of this book.
If you're a FreeBSD (or Linux, or Unix) sysadmin, then you need this book; it has a *lot* of hard-won knowledge, and will save your butt more than you'll be comfortable admitting.
You can purchase FreeBSD Mastery: Storage Essentials from amazon.com. Slashdot welcomes readers' book reviews (sci-fi included) -- to see your own review here, read the book review guidelines, then visit the submission page. If you'd like to see what books we have available from our review library please let us know.
The discussion of SMART disk monitoring is one of the best introductions to this subject I've ever read, and should serve *any* sysadmin well, no matter what OS they're dealing with; I plan on keeping it around for reference until we no longer use hard drives. RAID is covered, of course, but so are more complex setups — as well as UFS recovery and repair for when you run into trouble.
Disk encryption gets three chapters (!) full of details on the two methods in FreeBSD, GBDE and GELI. But just as important, Lucas outlines why disk encryption might *not* be the right choice: recovering data can be difficult or impossible, it might get you unwanted attention from adversaries, and it will *not* protect you against, say, an adversary who can put a keylogger on your laptop. If it still make sense to encrypt your hard drive, you'll have the knowledge you need to do the job right.
I said that this covers *almost* everything you need to know, and the big omission here is ZFS. It shows up, but only occasionally and mostly in contrast to other filesystem choices. For example, there's an excellent discussion of why you might want to use FreeBSD's plain UFS filesystem instead of all-singing, all-dancing ZFS. (Answer: modest CPU or RAM, or a need to do things in ways that don't fit in with ZFS, make UFS an excellent choice.) I would have loved to see ZFS covered here — but honestly, that would be a book of its own, and I look forward to seeing one from Lucas someday; when that day comes, it will be a great companion to this book, and I'll have Christmas gifts for all my fellow sysadmins.
One big part of the appeal of this book (and Lucas' writing in general) is that he is clear about the tradeoffs that come with picking one solution over another. He shows you where the sharp edges are, and leaves you well-placed to make the final decision yourself. Whether it's GBDE versus GELI for disk encryption, or what might bite you when enabling soft updates journaling, he makes sure you know what you're getting into. He makes recommendations, but always tells you their limits.
There's also Lucas' usual mastery of writing; well-written explanations with liberal dollops of geek humor that don't distract from the knowledge he's dropping. He's clear, he's thorough, and he's interesting — and that's an amazing thing to say about a book on filesystems.
Finally, the technical review was done by Poul Henning-Kamp; he's a FreeBSD developer who wrote huge parts of the GEOM and GBDE systems mentioned above. That gives me a lot of warm fuzzies about the accuracy of this book.
If you're a FreeBSD (or Linux, or Unix) sysadmin, then you need this book; it has a *lot* of hard-won knowledge, and will save your butt more than you'll be comfortable admitting.
You can purchase FreeBSD Mastery: Storage Essentials from amazon.com. Slashdot welcomes readers' book reviews (sci-fi included) -- to see your own review here, read the book review guidelines, then visit the submission page. If you'd like to see what books we have available from our review library please let us know.
In real world cases, this scenario happens:
1: Person loses their laptop/USB flash drive/storage media.
2: Someone finds it and examines it, or hands it to someone who can.
3: Stuff is found on there.
4: Front page news.
Just by having some form of disk encryption, preferably something that protects the entire machine (like geli)... that adds a large amount of security. A lost laptop goes from being a major corporate panic to becoming "just" a hardware loss, especially if the laptop has some mechanism like a removable USB flash drive or a TPM chip (which locks out for longer times the more failed guesses are attempted), and not just a passphrase that can be brute forced.
For most people, encryption is a no brainer. Turn it on, set a passphrase, forgot about it, except when after a reboot.
Now when people start mentioning rubber hose decryption (xkcd.com/538), this is generally not something everyone faces. However, there are other tools for that for plausible deniability, such as TC and its successors.
FDE encryption on a laptop that goes places should be considered a must, regardless of OS. Laptops and external media need some protection, and in most cases, the thief will boot the laptop up, see a FDE prompt, shrug, format the box, install a Windows variant, and pass it to another fence somewhere else to be sold.
As always, backups go without saying. Disk encryption and SSDs make this more important, because a TRIM means that the data isn't just marked as gone... it is -gone-, as in the physical cells has been zeroed out by the background garbage collector, and nobody is going to recover them. There are many ways to effectively back data up securely, and that is something left as an exercise to the reader.
Common sense says turn disk encryption on with a laptop, plain and simple.