Re: Do we need multiple REDOLOG member if it is already on SAN box?

From: John Hurley <>
Date: Tue, 3 May 2011 16:51:32 -0700 (PDT)
Message-ID: <>


# I did not know when I wrote that that the reason I hadn't seen too
many cow-orkers that morning was because two disks had failed over the weekend in a san that was set up for one disk failure.  Fortunately not one for the db's, just one that everybody else uses.

... One of the principal reasons for the Barf party strikes again eh?

All the sales reps will try to tell you that their customers just don't see multiple simultaneous failures in a RAID 5 setup and that "everyone" is running their production databases in RAID 5.

A production Data Warehouse maybe. Not my production OLTP systems thank you very much.

Not that a 2 disk failure cannot bring down a RAID 10 setup as it can if it is the right 2 disks ... just less likely.

# I haven't been keeping close track, but I think that means over 10
years, a once-in-100-year event approximately every other year for one (distributed) site.

... Man you guys just are living right ... starting to see why they keep you around year after year.

# Of course, they've had a few once-in-23,000-year events in the nuke
industry lately, so I guess that's not the worst.

... Guess earthquakes and tsunamis don't pay much attention to predicted failure rates. Received on Tue May 03 2011 - 18:51:32 CDT

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