From what i’ve learned the H710 controller still uses a battery backed cache and uses NV Flash to save the contents… 10 years of cache storage (vs 72 hours with just battery). Doesn’t seem like Dell provides a product like the…
Comment: Looking for RAID Controller without Battery Learning problems ?
March 7, 2013 By 11 Comments
Comment: Looking for RAID Controller without Battery Learning problems ?
March 1, 2012 By 11 Comments
… you have noted, the data write-back should never be battery dependent. Issues that crop up due to bad data write… real PITA, took sometime to figure out that the battery discharge-charge learn cycle was causing a big mess-up. Give us…
Comment: Battery Learning still problem many years after
February 11, 2011 By 7 Comments
Peter, On the HP P800, at least, you can have two batteries, and the learning phases are done alternately so a battery is always available. Regards, Jeremy
Comment: Looking for RAID Controller without Battery Learning problems ?
August 31, 2012 By 11 Comments
…. We can use API calls to schedule and monitor the learn cycle (despite Dell saying you can’t), but still a…, 620, 720, etc.) seems to be NV Flash and no battery, so we’ll see how well that works as we…
Comment: The perils of uniform hardware and RAID auto-learn cycles
November 16, 2010 By 16 Comments
… the battery reaches 25%, so we began alerting on this metric. I’m curious if you recommended the customer disable the learning…
Comment: RAID System performance surprises
June 21, 2010 By 7 Comments
Hey folks, Once I got MegaCli installed (on cent) that gives enough info to go on to disable battery relearn. This guy wrote it up and his instructions are explicit and effective. http://yo61.com/dell-drac-bbu-auto-learn-tests-kill-disk-performance.html -sean
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… are. I can also get information about the all-important battery-backed write cache, how it’s configured and what its… rundown over every option in the file. But again, you learn quickly if something strange is here. This whole time I…
Comment: How much overhead DRDB could cause ?
June 3, 2008 By 4 Comments
…% latency overhead. Now when you introduce a RAID controller with battery-backed write cache to the setup (and you should), your…. And just in case other readers here are interested in learning more about DRBD performance tuning considerations, I encourage you to…
Post: How much overhead DRDB could cause ?
June 2, 2008 By 4 Comments
… performing well at the same time you must have BBU (Battery backed up unit) on your hardware RAID card or something… lesson – do not take the overhead as a number but learn where this overhead comes from so you can find how…
Post: Evaluating IO subsystem performance for MySQL Needs
March 5, 2008 By 23 Comments
…). The system I’m testing this on has 256MB BBU (Battery Backed up Cache) on RAID controller so we will test… especially playing with data size a bit you will well learn how your cache behaves. Were even more so interested about…
