John R Pierce wrote:
On 11/3/2017 1:31 AM, hw wrote:
2.5" SAS drives spinning at 10k and 15k RPM are the performance solution for online storage, like databases and so forth. also make more sense for large arrays of SSDs, as they don't even come in 3.5". With 2.5" you can pack more disks per U (24-25 2.5" per 2U face, vs 12 3.5" max per 2U)... more disks == more IOPS.
That´s not for storage because it´s so expensive that you can only use it
for the limited amounts of data that actually benefit from, or require,
the advantage in performance. For this application, it makes perfectly
sense.
online high performance storage, vs nearline/archival storage. the first needs high IOPS and high concurrency. the 2nd needs high capacity, fast sequential speeds but little or no random access.. two completely different requirements. both are 'storage'.
Not really. You don´t put things into storage you´re using frequently or
all the time. Instead, you keep them around where you can get at them
easily when you need them. Usually, that isn´t a lot of things.
Storage is for things you don´t use as much and usually provides a lot of
room to put things.
3.5" SATA drives spinning at 5400 and 7200 rpm are the choice for large capacity bulk 'nearline' storage which is typically sequentially written once
Why would you write them only once? Where are you storing your data when you
do that?
I meant to say write occasionally. on a nearline bulk system, files tend to get written sequentially, and stored for a long time.
Data in a database is stored for a long time as well, and a lot of it isn´t
written to often, or basically only once. A spreadsheet may be written to
more often, yet you might put it into storage because you have large amounts
of data like that.
For large amounts of data, 2.5" disks aren´t suitable. Since there are like
no servers at all you can buy used that fit 3.5" disks, I´m wondering what
everyone does about storage. The servers that fit 3.5" disks were all sold a
couple years ago, and even then it was difficult to find anything that would
have room for more than 6 disks.
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