[Dovecot] SSD drives are really fast running Dovecot

[Stan Hoeppner]

David Jonas put forth on 1/14/2011 2:08 PM:

> Raid10 is our normal go to, but giving up half the storage in this case
> seemed unnecessary. I was looking at SAS drives and it was getting
> pricy. I'll work SATA into my considerations.

That's because you're using the wrong equation for determining your disk storage
needs.  I posted a new equation on one of the lists a week or two ago.
Performance and reliability are far more important now than total space.  And
today performance means transactional write IOPS not streaming reads.  In
today's world, specifically for transaction oriented applications (db and mail)
smaller faster more expensive disks are less expensive in total ROI that big fat
slow drives.  The reason is that few if any organizations actually need 28TB (14
2TB Cavier Green drives--popular with idiots today) of mail storage in a single
mail store.  That's 50 years worth of mail storage for a 50,000 employee
company, assuming your employees aren't allowed porn/video attachments, which
which most aren't.

>> Having both SSD and spinning drives in the same SAN controller eliminates the
>> high latency low bandwidth link you were going to use with drbd.  It also
>> eliminates buying twice as many SSDs, PCIe RAID cards, and disks, one set for
>> each cluster server.  Total cost may end up being similar between the drbd and
>> SAN based solutions, but you have significant advantages with the SAN solution
>> beyond those already mentioned, such as using an inexpensive FC switch and
>> attaching a D2D or tape backup host, installing the cluster filesystem software
>> on it, and directly backing up the IMAP store while the cluster is online and
>> running, or snapshooting it after doing a freeze at the VFS layer.
> 
> As long as the SATAboy is reliable I can see it. Probably would be
> easier to sell to the higher ups too. They won't feel like they're
> buying everything twice.

Hit their website and look at their customer list and industry awards.  They've
won them all pretty much.  Simple, reliable, inexpensive SAN storage arrays.  No
advanced features such as inbuilt snapshots and the like.  Performance isn't the
fastest on the market but it's far more than adequate.  The performance per
dollar ratio is very high.  I've installed and used a SATABlade and SATABoy
myself and they're extremely reliable, and plenty fast.  Those were spinning
models.  I've not used SSDs in their chassis yet.

http://www.nexsan.com

You configure the controller and drives via a web interface over an ethernet
port.  There's a lot to love in the way Nexsan builds these things.  At least,
if you're a HardwareFreak like me.

-- 
Stan