WildFire ESS Performance
WildFire ESS technology delivers
superior write performance. Our patented solution takes
the random stream of writes arriving at a block device
and converts them into linear writes with embedded
control information. This has a couple of immediate
performance benefits.
Storage
devices are most efficient when writing linearly.
If you want maximum megabytes per second, write
linearly. This is true of unmanaged Flash. This is true
even with the best Flash SSDs.
RAID works
best with linear writes. Random writes to RAID
kill write performance. With RAID-1 and RAID-10, you
throw away half your write bandwidth. RAID-5 and RAID-6
are much worse. The solution is to write linearly. If
you write linearly to RAID-5/6, and especially if you
can write linearly and perfectly aligned with RAID
stripes, you can write at the linear speed of the
underlying devices. WildFire knows exactly what RAID
wants and delivers perfectly aligned writes ensuring
absolute maximum throughput.
Writing
linearly is not only faster, it is safer. When
you write randomly, file systems and disk drives often
have to play all sorts of games to optimize performance.
It is these games that scramble file systems after a
crash. WildFire's design never re-orders writes, so data
is always clean on the next mount. Random writes also
lead to a plethora of ills for storage devices. Flash
wears out much faster and hard drives use more power and
fail more often.
What does this
mean for performance. WildFire arrays write
faster than would seem possible. For small arrays, writes
happen at "drive bandwidth" regardless of block size and
queue depth. 4K random writes at 300K IOPS q=1 is
easily achieved. 1.8M 4KB random write IOPS is 7.2GB/sec. The WildFire engine is a
streaming solution that writes at the speed of the disks
regardless of the workload.
Even hard drives are
transformed by WildFire technology. A 7200 RPM hard disk
is lucky to write at 200 IOPS. At 4K, this is less than
1MB/sec. With WildFire, the HDD writes linearly at
100MB/sec or 25K IOPS. 25,000 IOPS is not a number
normally associated with rotating disks. With an array
of 12 HDDs running RAID-5, the writes can exceed 250K 4K
IOPS.
Small random writes
through WildFire are so fast, and so cheap in terms of
overhead, that you can ignore them. In many cases, the
array is completely dominated by read overhead as writes
are nearly free.
Random write
overhead just drops off the radar. In many
environments, the overhead of random writes is critical.
Look at tuning guides for file systems like EXT4 and you
see options like "noatime". You see users recommending
EXT2 without a journal to reduce Flash wear. The goal of
all of these tweaks is to eliminate little random
writes. With many storage solutions, these small random
writes are enough to push the array over the edge. With
WildFire, these random writes are just a tiny part of
the linear stream, and are not even measurable, let
alone noticeable, even on a busy array.
Even if you think you
don't have an application that does a lot of random
writes, you will still benefit from WildFire technology.
Our perfect alignment with RAID-5 and RAID-6 delivers
more write bandwidth than your drives have ever
delivered, whether they are SSDs or HDDs. Faster writes
leaves more time for reads. Shockingly faster writes and
more time for reads gives you better application
responsiveness.
WildFire
technology is more than fast. Performance is
just the beginning. Check out our white papers on Flash
wear, and getting the most of SMR HDDs..
