Musings on storage, tuning, backups and more – delivered with a no-nonsense approach. By Dimitris Krekoukias
(edit: fixed the images)
After a long hiatus, we return to our regularly scheduled programming with a 2-part series that will address some wild claims Oracle has been making recently.
I’m pleased to introduce Jeffrey Steiner, ex-Oracle employee and all-around DB performance wizard. He helps some of our largest customers with designing high performance solutions for Oracle DBs:
Continue reading “When competitors try too hard and miss the point”
As the self-proclaimed storage vigilante, I will keep bringing these idiocies up as I come across them.
So, the latest “thing” now is selling systems using “Raw IOPS” numbers.
Simply put, some vendors are selling based on the aggregate IOPS the system will do based on per-disk statistics and nothing else.
They are not providing realistic performance estimates for the proposed workload, with the appropriate RAID type and I/O sizes and hot vs cold data and what the storage controller overhead will be to do everything. That’s probably too much work.
Continue reading “So now it is OK to sell systems using “Raw IOPS”???”
<I understand this extremely long post is redundant for seasoned storage performance pros – however, these subjects come up so frequently, that I felt compelled to write something. Plus, even the seasoned pros don’t seem to get it sometimes… 🙂 >
IOPS: Possibly the most common measure of storage system performance.
IOPS means Input/Output (operations) Per Second. Seems straightforward. A measure of work vs time (not the same as MB/s, which is actually easier to understand – simply, MegaBytes per Second).
How many of you have seen storage vendors extolling the virtues of their storage by using large IOPS numbers to illustrate a performance advantage?
How many of you decide on storage purchases and base your decisions on those numbers?
However: how many times has a vendor actually specified what they mean when they utter “IOPS”? 🙂
For the impatient, I’ll say this: IOPS numbers by themselves are meaningless and should be treated as such. Without additional metrics such as RAID type, randomness, latency, read vs write % and I/O size (to name a few), an IOPS number is useless.
And now, let’s elaborate… (and, as a refresher regarding the perils of ignoring such things when it comes to sizing, you can always go back here).
Most are familiar with Hanlon’s Razor:
Never attribute to malice that which is adequately explained by stupidity.
A variation of that is:
Never attribute to malice that which is adequately explained by stupidity, but don’t rule out malice.
Continue reading “NetApp vs EMC usability report: malice, stupidity or both?”
A bit of a controversial title, no?
Allow me to elaborate.
EMC posted a new SPEC SFS result as part of a marketing stunt (which is working, look at what I’m doing – I’m talking about them, if only to clear the air).
Continue reading “EMC conclusively proves that VNX bottlenecks NAS performance”