ZFS? Why you should care about ZFS?

zfs_logoThere’s a lot of buzz about the Zettabyte File System from Sun Oracle, which has been included for a while in both Solaris and OpenSolaris.  (Distributions based on Opensolaris like Nexenta have it.  Also some BSD distributions have it).

In general, file systems are not exactly glamorous.  HFS?  UFS? VxVM?  Who cares.  It’s a file system, right?

ZFS has some serious juicy goodness.  Personally, I think as time goes on, you’ll see more and more ZFS (or at least ZFS-like file systems) used on production servers, especially file servers.  Like NexentaStor.

One of the things I like best about ZFS is that the developers worked hard to make it easy to use.  ZFS is a combination of file system and volume manager.   What this means is that ZFS in dead simple to administer.  Most commands are one liners, and take the place of what would have been whole strings of commands with other volume managers.

Believe it or not, most file systems *DO NOT* actually detect or repair “bit rot”.  Hopefully you have underlying hardware like a RAID controller to handle that.  Even if you do, all it usually does is perhaps complain about “corruption detected”.  Bits flip and files get whacked more often than you think.  Not with ZFS.  ZFS uses elaborate checksumming to detect and repair problems.

Along similar lines, ZFS has atomic writes.  Either something is written to disk correctly, or it is not written at all.  You see high end databases like this, but not file systems.  What this means is that you can literally pull the plug on a server during a big write, and the file system stays intact.  No more fsck!

Here’s ten reasons to reformat your hard drives.


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