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ZFS

What is RAID-Z?

The mission of ZFS was to simplify storage and to construct an enterprise level of quality from volume components by building smarter software — indeed that...

The mission of ZFS was to simplify storage and to construct an enterprise level of quality from volume components by building smarter software — indeed that notion is at the heart of the 7000 series. An important piece of that puzzle was eliminating the expensive RAID card used in traditional storage and replacing it with high performance, software RAID. To that end, Jeff invented RAID-Z; it's key innovation over other software RAID techniques was to close the "RAID-5 write...

A Logzilla for your ZFS box

A key component of the ZFS Hybrid Storage Pool is Logzilla, a very fast device to accelerate synchronous writes. This component hides the write latency of disks...

A key component of the ZFS Hybrid Storage Pool is Logzilla, a very fast device to accelerate synchronous writes. This component hides the write latency of disks to enable the use of economical, high-capacity drives. In the Sun Storage 7000 series, we use some very fast SAS and SATA SSDs from STEC as our Logzilla &mdash the devices are great and STEC continues to be a terrific partner. The most important attribute of a good Logzilla device is that it have very low latency for...

Triple-Parity RAID-Z

Double-parity RAID, or RAID-6, is the de facto industry standard forstorage; when I started talking about triple-parity RAID for ZFS earlierthis year, the need...

Double-parity RAID, or RAID-6, is the de facto industry standard forstorage; when I started talking about triple-parity RAID for ZFS earlierthis year, the need wasn't always immediately obvious. Double-parity RAID, ofcourse, provides protection from up to two failures (data corruption or the wholedrive) within a RAID stripe. The necessity of triple-parity RAIDarises from the observation that while hard drive capacity has roughly followedKryder's law, doubling annually, hard...

Expand-O-Matic RAID-Z

I was having a conversation with an OpenBSD user and developer the other day, and he mentioned some ongoing work in the community to consolidate support for...

I was having a conversation with an OpenBSD user and developer the other day, and he mentioned some ongoing work in the community to consolidate support for RAID controllers. The problem, he was saying, was that each controller had a different administrative model and utility -- but all I could think was that the real problem was the presence of a RAID controller in the first place! As far as I'm concerned, ZFS and RAID-Z have obviated the need for hardware RAID...

gzip for ZFS update

The other day I posted about a prototype I had created that adds a gzip compression algorithm to ZFS. ZFS already allows administrators to choose to compress...

The other day I posted about a prototype I had created that adds a gzip compression algorithm to ZFS. ZFS already allows administrators to choose to compress filesystems using the LZJB compression algorithm. This prototype introduced a more effective -- albeit more computationally expensive -- alternative based on zlib.As an arbitrary measure, I used tar(1) to create and expand archives of an ON (Solaris kernel) source tree on ZFS filesystems compressed with lzjb and gzip...

a small ZFS hack

I've been dabbling a bit in ZFS recently, and what's amazing is not just how well it solved the well-understood filesystem problem, but how its design opens the...

I've been dabbling a bit in ZFS recently, and what's amazing is not just how well it solved the well-understood filesystem problem, but how its design opens the door to novel ways to manage data. Compression is a great example. An almost accidental by-product of the design is that your data can be stored compressed on disk. This is especially interesting in an era when we have CPU cycles to spare, many too few available IOPs, and disk latencies that you can measure with a...

Double-Parity RAID-Z

When ZFS first started, it was just Jeff trying to pair old problems with new solutions in margins too small to contain either. Then Matt joined up to bring...

When ZFS first started, it was just Jeff trying to pair old problems with new solutions in margins too small to contain either. Then Matt joined up to bring some young blood to the project. By the time the project putback, the team had grown to more than a dozen. And now I've been pulled in -- if only for a cameo.When ZFS first hit the streets, Jeff wrote about RAID-Z, an implementation of RAID designed for ZFS. RAID-Z improves upon previous RAID schemes primarily in that it...