Archive for the ‘ZFS’ Category

Another reason Apple misses ZFS

Apple recently announced a new iMac model — in itself, only as notable as the seasons — but with an interesting option: users can choose to have both an HDD and an SSD. Their use of these two is absolutely pedestrian, as noted on the Apple store: If you configure your iMac with both the [...]

Posted on May 20, 2011 at 8:02 am by ahl · Permalink · 5 Comments
In: ZFS · Tagged with: , , ,

ZIL analysis from Chris George

Chris George from DDRdrive put together a great presentation at the OpenStorage summit looking at the ZFS intent log (ZIL), and how their product is particularly well-suited as a ZIL device. Chris did a particularly interesting analysis of the I/O pattern ZFS generates to ZIL devices (using DTrace of course). With writes to a single [...]

Posted on November 15, 2010 at 2:48 am by ahl · Permalink · Comments Closed
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RAID-Z at the OpenStorage Summit

I had the chance to speak at the OpenStorage Summit a couple of weeks ago about RAID-Z (the ZFS implementation of RAID). The talk was an accumulation of blog posts and articles written by me and others as well as quite a bit of new material that’s been building up. The talk was an overview [...]

Posted on November 10, 2010 at 8:28 pm by ahl · Permalink · Comments Closed
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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 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 [...]

Posted on July 21, 2010 at 11:46 pm by ahl · Permalink · 8 Comments
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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 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 [...]

Posted on July 19, 2010 at 11:29 pm by ahl · Permalink · Comments Closed
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Triple-Parity RAID-Z

Double-parity RAID, or RAID-6, is the de facto industry standard for storage; when I started talking about triple-parity RAID for ZFS earlier this year, the need wasn’t always immediately obvious. Double-parity RAID, of course, provides protection from up to two failures (data corruption or the whole drive) within a RAID stripe. The necessity of triple-parity [...]

Posted on July 21, 2009 at 11:48 pm by ahl · Permalink · 14 Comments
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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 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 [...]

Posted on April 7, 2008 at 9:59 pm by ahl · Permalink · 16 Comments
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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 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 [...]

Posted on January 31, 2007 at 10:30 pm by ahl · Permalink · 7 Comments

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 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 [...]

Posted on January 29, 2007 at 12:08 am by ahl · Permalink · 10 Comments

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 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 [...]

Posted on June 18, 2006 at 3:00 pm by ahl · Permalink · 7 Comments
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