@@ 1,427 @@
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@@ 1,322 @@
+% vim: tw=500
+\documentclass{lug}
+
+\usepackage{fontspec}
+\usepackage{hyperref}
+\usepackage{graphicx}
+
+\title{ZFS}
+\author{Jordan Newport}
+
+\begin{document}
+
+\section{Introduction}
+
+% why am I giving this talk? I have an obsession with Z-branded computing products.
+% zfs, zsh, zathura, z workstations (z2 mini, zbook 15), zcentral remote boost...
+
+% really, though, lots of cool features that make it good to use, particularly for servers (imo)
+
+\begin{frame}{What is ZFS?}
+ \begin{itemize}
+ \item Originally the ``Zettabyte File System''; now just known as ZFS % that didn't stick
+ \item ZFS is a filesystem with a lot of cool features
+ \item ZFS is {\em also} a volume manager
+ \item Doing both gives ZFS access to some cool features % and some performance benefits for those features
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{Goals of this talk}
+ You should...
+ \begin{itemize}
+ \item be familiar with the basics of ZFS
+ \item hear about some cool features that inspire you to compose them in brand new ways, UNIX-style
+ \item be able to communicate intelligently about ZFS % you know, instead of being the noob you are right now
+ \item think ZFS is cool, so you want to play with it % whether or not you actually have a specific need to
+ \item have resources to learn more
+ \end{itemize}
+ \pause
+
+ You should NOT...
+ \begin{itemize}
+ \item come out of this knowing a crapton of console commands and flags
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{Which ZFS? Or, a quick history}
+ \begin{itemize}[<+->]
+ \item ZFS was originally made for Sun's Solaris operating system. Work started in 2001 and it was released in 2004.
+ \item ZFS was open-sourced as part of the OpenSolaris project from 2005-2010.
+ \end{itemize}
+
+
+\end{frame}
+
+\begin{frame}
+ % Enter Larry Ellison and his yacht obsession.
+ \includegraphics[width=1.0\textwidth]{graphics/Rising_Sun_(yacht)_2006.jpg}
+ \tiny
+ image by Flickr user reivax - https://www.flickr.com/photos/reivax/349438581/in/photostream/, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=22867828
+\end{frame}
+
+\begin{frame}{A Quick History, continued}
+ \begin{itemize}[<+->]
+ \item Oracle bought Sun and closed-sourced ZFS in 2010
+ \item The OpenZFS projectwas created in 2013 to manage development efforts on the core of ZFS, after people forked it
+ \item OpenZFS is open source under the CDDL, which is copyleft but not viral
+ \item Platforms maintain their own interfaces
+ \item Oracle ZFS and OpenZFS are no longer compatible
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{A quick digression: ZFS on Linux}
+ \begin{itemize}
+ \item Used to be considered bad because of subtle incompatibilities between Linux ZFS and {\em everyone else's}
+ \item This meant you could bork shared pools
+ \item I haven't researched this in specific, but the zeitgeist suggests that ZFS on Linux is good now % or that there are ways to dodge the badness
+ \item Due to some arcane combination of license incompatibilities and the relative newness of good support, ZFS is not as available as you might hope
+ \item You might even have to load the kernel module yourself!
+ \item \texttt{zfs-linux} in the AUR
+ \item Ubuntu has some kind of special thing
+ \end{itemize}
+
+ % \includegraphics[width=0.1\textwidth]{graphics/freebsd.png}
+\end{frame}
+
+\begin{frame}{A quick digression: ZFS on Linux}
+ \begin{itemize}
+ \item Used to be considered bad because of subtle incompatibilities between Linux ZFS and {\em everyone else's}
+ \item This meant you could bork shared pools
+ \item I haven't researched this in specific, but the zeitgeist suggests that ZFS on Linux is good now % or that there are ways to dodge the badness
+ \item Due to some arcane combination of license incompatibilities and the relative newness of good support, ZFS is not as available as you might hope
+ \item You might even have to load the kernel module yourself!
+ \item \texttt{zfs-linux} in the AUR
+ \item Ubuntu has some kind of special thing
+ \end{itemize}
+
+ \includegraphics[width=0.1\textwidth]{graphics/freebsd.png} % or you could just use FreeBSD. You heathens
+
+ % this is the BUG now
+ % BSD user group
+\end{frame}
+
+\begin{frame}{So what is a filesystem?}
+ You want to store some information.
+
+ Your filesystem will help in some or all of these ways:
+ \begin{itemize}[<+->]
+ \item Organizes your storage medium into physical units
+ \item Organizes units into named files
+ \item Supports a (hierarchical) directory structure
+ \item Stores metadata on files
+ \item Provides some kind of interface to let you interact with these things % and, say, make or read files
+ % acls, encryption, whatever
+ % all this may include disk operations
+ % internal utilities, user utilities, apis
+ \item Maintains integrity, does backups, handles errors
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{So what is a volume manager?}
+ You have one or more physical volumes or partitions thereof.
+
+ The volume manager turns this into some number of logical volumes that can be presented to a filesystem.
+
+ Not every system has a serious volume manager, but if yours does, here's what it will do:
+
+ \begin{itemize}[<+->]
+ \item Provide/manage redundancy
+ \item Improve performance via ``striping''
+ \item Resize logical volumes, possibly live with an online filesystem
+ \end{itemize}
+
+ % zfs!
+
+\end{frame}
+
+\begin{frame}{ZFS}
+ 3 goals:
+ \begin{itemize}
+ \item Data integrity % your data should not be corrupted
+ \item Pooled storage % in a moment
+ \item Performance % these features should be offered with >= performance to other filesystems
+ \end{itemize}
+\end{frame}
+
+\section{\texttt{zpool}}
+
+\begin{frame}{Zpool}
+ Zpool is the volume-management half of ZFS.
+
+ Zpool makes block devices into pools, which are just aggregations of one or more disks.
+
+ Making a pool is as simple as
+
+ \texttt{zpool create poolname [devices]}.
+
+ You specify mirroring/RAID at creation time. % explained soon
+\end{frame}
+
+\begin{frame}{Redundancy and integrity}
+ \begin{itemize}[<+->]
+ \item ZFS has something called RaidZ, which is just a set of RAID options with better performance since it's integrated with the filesystem
+ \item ZFS also has mirroring % literally just exact copies
+ \item You can set up a pool of hot spares % pools fail over into these disks until you replace/promote them
+ \item ZFS has pool-level checksumming and automatic repair % if in mirror or raid
+ \item ZFS makes it trivial to replace both working and failed devices
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{Backups}
+ \begin{itemize}[<+->]
+ \item You can import or export pools between machines or on the same machine % this can be live
+ \item Pools can be checkpointed % like a dataset snapshot
+ \item Pools can be split or de-redudancied at any time
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{Performance}
+ \begin{itemize}[<+->]
+ \item Pools can have cache devices
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{Properties}
+ These can all be set at creation, import, or even while running.
+ \begin{itemize}[<+->]
+ \item Readonly
+ \item Autoexpand
+ \item Autoreplace
+ \item Permissions delegation
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{Devices}
+ Devices can be added or removed at any time.
+
+ They can be added as new mirrors, or they can be added to existing mirrors/non-redundant pools to expand the pool.
+
+ Devices can be turned on or off at any time.
+\end{frame}
+
+\begin{frame}{Administration}
+ Zpool and ZFS admin ops can be run as LUA scripts via zfs-program.
+
+ This is in addition to cron. % or whatever systemd monstrosity you come up with on Linux
+\end{frame}
+
+\section{\texttt{zfs}}
+
+\begin{frame}{ZFS}
+ ZFS is the filesystem half of the ZFS system.
+
+ It creates filesystems on top of zpools.
+
+ This is as simple as
+
+ \texttt{zfs create poolname/filesystem-name}.
+
+ ZFS is copy-on-write. This means that when you write a file, it's actually copied, so that the original data is never lost.
+
+ % this makes snapshots easy because you have an easy way to store only modified data in the snapshot
+
+ % fyi: a lot the suggested use cases of these features are related to compression
+\end{frame}
+
+\begin{frame}{Datasets}
+ Filesystems are known in ZFS as datasets.
+
+ \pause
+
+ It is not clear why.
+
+ \pause
+
+ % I *am* mostly going to call them datasets, because that's what the docs call them
+
+ You can make and destroy datasets at any time. They may be nested inside other datasets.
+
+ Datasets grow up to the size of the pool. All datasets in a shared pool may grow until their total size reaches the size of a pool.
+ % what this means is that you don't have to preallocate dataset sizes; they just grow until they can't
+
+ You can make ``volume'' datasets, which are block devices and can be used for other filesystems.
+\end{frame}
+
+\begin{frame}{Dataset management}
+ \begin{itemize}[<+->]
+ \item Datasets can be renamed
+ \item This allows them to be given different parents and moved between pools.
+ % different parents -> different inherited properties
+ \item Dataset properties can be changed at any time
+ \begin{itemize}
+ \item ACL stuff
+ \item Readonly
+ \item NFS share
+ \end{itemize}
+ \item Just like pools, datasets have good ACL control and delegation of permissions
+ \item Datasets also interact well with FreeBSD jails if you're into that
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{Snapshots}
+ Snapshots are arguably the ``killer feature'' of ZFS.
+
+ \begin{itemize}[<+->]
+ \item Snapshots are per-dataset % (not per-file or directory)
+ \item Snapshots are stored as diffs between the current filesystem state and the filesystem state when they were taken
+ % storage using only the changed parts of COW
+ % this means they grow as you change more things, but start at 0
+ \item This means that for many use cases, snapshots will be very storage-efficient
+ \item Because of their small size and effective storage, snapshots can be rolled back live, and in a safe and consistent fashion
+ % explain consistency?
+ \item You can diff between different snapshots % no specific differences, but will show what files were added/deleted/changed
+ \item Not only can you roll back snapshots, you can roll back individual files from snapshots as well
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{More on snapshots}
+ \begin{itemize}[<+->]
+ \item Snapshots can also be cloned, which basically just copies the entire filesystem
+ \item Snapshots can also be sent to other datasets to be restored using \texttt{zfs send}
+ \item They canalso be piped directly to \texttt{zfs receive} on a live, running filesystem
+ \item This can also be done over ssh
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{Pool space}
+ \begin{itemize}[<+->]
+ \item You can set quotas for datasets, users, and groups
+ \item You can also reserve a certain amount of space for a dataset % for, say, important growing files or log files
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{Compression}
+ \begin{itemize}[<+->]
+ \item It's very easy to create a compressed dataset
+ \item New versions of ZFS have very good compression
+ \item ZFS 5000 has LZ4 compression and basically no performance tradeoff
+ \begin{itemize}
+ \item Writing compressed data improves your disk IO situation % which balances the time you needed to compress
+ \item If ZFS detects that it's not compressing enough on the first block, then it aborts compression and writes uncompressed % to save time
+ \end{itemize}
+ \item Deduplication also exists, although compression is almost always better % noting copies of existing blocks rather than rewriting them
+ \end{itemize}
+\end{frame}
+
+\section{Resources}
+
+\begin{frame}{Resources}
+ The Wikipedia page for ZFS is the source of a lot of the background.
+
+ The two resources I looked at for technical content are (hyperlinks):
+
+ \begin{itemize}
+ % FreeBSD man pages have a reputation as being mildly better than Linux ones, and ZFS is first-class on FreeBSD
+ \item The FreeBSD man pages for \href{https://www.unix.com/man-page/freebsd/8/zpool/}{zpool},
+ \href{https://www.unix.com/man-page/freebsd/8/zfs/}{zfs},
+ and \href{https://www.unix.com/man-page/freebsd/8/zfs-program/}{zfs-program}
+ \item The \href{https://docs.freebsd.org/en/books/handbook/zfs/}{FreeBSD System Administration Handbook's ZFS section}
+ \end{itemize}
+\end{frame}
+
+\end{document}
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