On 5/13/14 05:15 , Christian Balzer wrote:
On Tue, 13 May 2014 22:03:11 +1200 Mark Kirkwood wrote:
On thing that would put me off the 530 is lack on power off safety
(capacitor or similar). Given the job of the journal, I think an SSD
that has some guarantee of write integrity is crucial - so yeah the
DC3500 or DC3700 seem like the best choices.
All my machines have redundant PSUs fed from redundant circuits in very
high end datacenters backed up by the usual gambit of batteries and
diesel monsters.
So while you (and the people who's first comment about RAID controllers is
to mention that one should get a BBU) certainly have a point I'm happily
deploying 530s where they are useful.
If that power should ever fail, I'm most likely buried under a ton of
(optionally radioactive) rubble (Tokyo here) or if I'm lucky just that one
DC is flooded, in which case the data is lost as well. ^o^
Christian
TL;DR: Power outages are more common than your colo facility will admit.
In my 15 years, I've experienced 4 data center power outages in 3
different facilities.
I don't remember the reason for the first one... maybe a power company
transformer failure that went way outside of voltage specs? This was in
a "Tier 1" data-center, the day after a press release bragging about
their uptime.
For the second one, the facility was doing a pressure test of the Halon
system. Some pipes failed and dumped halon, which triggered facility
power cut. This was in a "Tier 1" data-center.
The third and forth were the same root cause in the same facility. The
electrical switch that cuts from utility power to UPS power failed half
way through the cut over. While replacing the switch (before everything
was wired up), a fail-over was accidentally triggered. This was a "Tier
2" data-center.
The first two happened before SSDs (although I lost a bunch of HDDs
during the Halon deployment). The 3rd power failure had no problems.
The 4th power failure killed a mirrored pair of Intel 320's that were
connected to a battery backed RAID controller. Both lost their sector
map, and had to be erased using the Intel SSD tool before they could be
used again.
I'm using the DC3700's for my journals.
--
*Craig Lewis*
Senior Systems Engineer
Office +1.714.602.1309
Email cle...@centraldesktop.com <mailto:cle...@centraldesktop.com>
*Central Desktop. Work together in ways you never thought possible.*
Connect with us Website <http://www.centraldesktop.com/> | Twitter
<http://www.twitter.com/centraldesktop> | Facebook
<http://www.facebook.com/CentralDesktop> | LinkedIn
<http://www.linkedin.com/groups?gid=147417> | Blog
<http://cdblog.centraldesktop.com/>
_______________________________________________
ceph-users mailing list
ceph-users@lists.ceph.com
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
