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quick_guide:power_protection [2017/12/05 11:25]
gcooper 		quick_guide:power_protection [2017/12/05 11:43] (current)
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 An important note to keep in mind when considering the power protection implications at your site: The nature of **datacenter-based computing mitigates (somewhat) the data corruption issues** discussed below. An important note to keep in mind when considering the power protection implications at your site: The nature of **datacenter-based computing mitigates (somewhat) the data corruption issues** discussed below.
  
-Everything concerning power in the datacenter (your servers and Windows desktop sessions) is backed up with fantastic power protection: separate A and B power, A and B industrial UPS systems, A and B diesel generators, etc.  The power has never gone down in our datacenter.  Clean, reliable power is the number one commodity sold by the datacenter.+Everything concerning power in the datacenter (your servers and Windows desktop sessions) is protected by **fantastic power protection**: 
 + 
 +  * Separate 'A' and 'B' power delivery 
 +  * 'A' and 'B' Industrial UPS Systems 
 +  * 'A' and 'B' Diesel Generators 
 +  * Regular Scheduled Testing of UPS and Generators 
 +  * Etc. 
 + 
 +**The power has never gone down in our datacenter**.  Clean, reliable power is the number one commodity sold by the datacenter.
  
 As an example of how datacenter-based (cloud) computing affects power protection calculations at your location, consider a power incident affecting a workstation PC that causes a Remote Desktop session to be disconnected.  If a connection to an RDP session is lost, the Windows session is left running in the datacenter, waiting for someone to reconnect.  No data is lost or corrupted in the datacenter.  Since no corruption happened in the datacenter, one might consider the implications (cost, maintenance) of protecting the remote workstations. As an example of how datacenter-based (cloud) computing affects power protection calculations at your location, consider a power incident affecting a workstation PC that causes a Remote Desktop session to be disconnected.  If a connection to an RDP session is lost, the Windows session is left running in the datacenter, waiting for someone to reconnect.  No data is lost or corrupted in the datacenter.  Since no corruption happened in the datacenter, one might consider the implications (cost, maintenance) of protecting the remote workstations.
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 Surge suppressors do not provide automatic voltage regulation (AVR).  They only clamp (limit) over-voltages.  Surge suppressors generally clamp at 330V to 500V...meaning your gear will see (be affected by) those over-voltage incidents.  Damage will occur over time.  Better-quality UPS units will regulate voltage (AVR feature, 'buck and boost'). Surge suppressors do not provide automatic voltage regulation (AVR).  They only clamp (limit) over-voltages.  Surge suppressors generally clamp at 330V to 500V...meaning your gear will see (be affected by) those over-voltage incidents.  Damage will occur over time.  Better-quality UPS units will regulate voltage (AVR feature, 'buck and boost').
  
-==== Test Your UPS ====+==== UPS Sizing ====
  
-Testing existing UPS units in-place is not simple and **failing UPS units can cause very difficult-to-troubleshoot problems**.  Generally, we mark UPS units when we install them with the date of installation.  Then, we refer to that date when any question of UPS efficacy comes up.  We have found new UPS units are generally quite reliable up to 2.5 years of age.  After that point, we just replace them rather than spend time troubleshooting them...it's just more cost-effective.+The sizing of your UPS (in volt-amps or watts) in relation to the load will determine your optimal UPS size (run-time).
  
-To test a UPS unit in place, we will generally reboot a PC just to the POST (BIOS) screen, then pause the boot (usually just by hitting the PAUSE or DEL key).  Then we yank the power cord so that the UPS cuts over to battery power.  If the PC stays up (doesn't immediately power off), we check the run-time.  If the UPS will keep the PC up for 5 or 10 minutes, we call that good.  While this is an unscientific test, it's fairly easy to do and indicative of the state of the UPS unit.+  * We generally use a 685VA (390W) smart UPS with automatic voltage regulation (AVR) for most PCs. 
 +  * We generally use **dual** 1500VA (900W) smart UPS units with AVR for servers with dual power supplies. 
 +    * Two 1500VA UPS units can probably support two running servers. 
 +    * On-battery run-time is dependent on the actual load.
  
-<note warning>If you just yank the power cord with the PC booted into Windows, there is a big chance you will cause filesystem damage (data loss) and Windows may not boot up again!</note>+==== Cost ====
  
-==== When the Power Goes Out ====+Yes, power protection is an expensive 'drag' that requires ongoing maintenance and cost.  But it is perilous to ignore.
  
-If the power goes out, and your PC continues to run on the UPS battery (beeping), shut down the PC gracefully so as not to damage the disk filesystem when the UPS battery runs out.+UPS units use lead-acid battery technology, like a car, and they fail predictably.  
  
-==== UPS Sizing ====+**UPS units must be replaced about every three years.**
  
-The sizing of your UPS (in volt-amps or watts) in relation to the load will determine your optimal UPS size (run-time).+===== Test Your UPS =====
  
-==== Cost ====+<note warning>If you just yank the power cord with the PC booted fully into the OS, there is a significant chance you will cause filesystem damage (data loss) and Windows may not boot up again!</note>
  
-Yes, power protection is an expensive 'drag' that requires ongoing maintenance and cost.  But it is perilous to ignore.+Testing existing UPS units in-place is not simple and **failing UPS units can cause very difficult-to-troubleshoot problems**.  Generally, we mark UPS units when we install them with the date of installation.  Then, we refer to that date when any question of UPS efficacy comes up.  We have found new UPS units are generally quite reliable up to 2.5 years of age.  After that point, we just replace them rather than spend time troubleshooting them...it's just more cost-effective. 
 + 
 +To test a UPS unit in place, we will generally reboot a PC just to the POST (BIOS) screen, then pause the boot (usually just by hitting the PAUSE or DEL key).  Then we yank the power cord so that the UPS cuts over to battery power.  If the PC stays up (doesn't immediately power off), we check the run-time.  If the UPS will keep the PC up for 5 or 10 minutes, we call that good.  While this is an unscientific test, it's fairly easy to do and indicative of the state of the UPS unit. 
 + 
 +===== When the Power Goes Out ===== 
 + 
 +If the power goes out, and your PC continues to run on the UPS battery (beeping), **shut down the PC gracefully** so as not to damage the disk filesystem when the UPS battery runs out.
  
-==== References ====+===== Reference =====
  
 A few references (among a great many): A few references (among a great many):
  
 http://www.cbldatarecovery.com/blog/data-recovery/top-causes-of-data-loss http://www.cbldatarecovery.com/blog/data-recovery/top-causes-of-data-loss
 +
 http://www.databackuponlinestorage.com/7_Causes_of_Data_Loss http://www.databackuponlinestorage.com/7_Causes_of_Data_Loss
 +
 https://www.imobie.com/support/top-5-causes-of-data-loss.htm https://www.imobie.com/support/top-5-causes-of-data-loss.htm
 +
 http://www.nerd4rent.com/reports/powerproblems.htm http://www.nerd4rent.com/reports/powerproblems.htm
 +
 http://members.tripod.com/thecomputerguy__/power.htm http://members.tripod.com/thecomputerguy__/power.htm
 +
 http://www.techrepublic.com/article/10-things-you-should-know-about-deploying-a-ups/ http://www.techrepublic.com/article/10-things-you-should-know-about-deploying-a-ups/
quick_guide/power_protection.1512498348.txt.gz · Last modified: 2017/12/05 11:25 by gcooper

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