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RAID5 FAILED after unexpected restart

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May 27, 2009 9:08:02 PM

Hi,

I have a question. I decided to used RAID 0 as system disk and RAID 5 as storage, both with enabled write cache on
INTEL STORAGE MATRIX ...

I had unexpected restart on VISTA, and after restart, RAID 5 volume started automaticali rebuilding ...

Why is this happening ? After unexpected restart, i loosed 1 disk, which is actually OK, and stupid system is rebuilding all data !

Can someone explain me, why is RAID so UNSAFE ?

Thx
a c 76 G Storage
May 27, 2009 9:19:43 PM

This is normal behavior. Just let it rebuild. Write cache should be enabled only if you have a UPS and a very stable system. Do you know why Vista crashed?
May 28, 2009 3:49:56 PM

but the write cache make it possible to have greater speeds .. why turn it off ?
And unexpected restart, will destroy all the data, because of write cache enabled ? It doesnt exist any utility to handle this ?
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a c 76 G Storage
May 28, 2009 6:51:06 PM

Write caching is great when you use a hardware RAID controller with battery backup. Good controllers won't allow write caching without a battery or when the battery is weak.

Write caching isn't a good idea on a PC that isn't on a UPS, is overclocked or not 100% stable. An unexpected restart causes a data loss and a rebuild is required because there is no way to determine if all drives are clean. This happens only if a write operation was in progress at failure time.
May 28, 2009 7:21:39 PM

make sure you have the latest intel matrix console .... v8.8 I believe...

In the prior version, the console itself caused most of the bsod which then caused constant rebuilds and verification.

V8.8 seems so much more stable without problems with hotswapping. I only got one BSOD from 8.8 and that was waking the computer from sleep, of which I now shut down and power up normally. Upon rebooting, the drives needed verification.

Leaving the cache on means that any data, especailly the OS using the swap files will not be written to the disk on sudden BSOD, which means that the disk is now dirty requiring either a verification or rebuild.

Sudden reboot on intel matrix raids always annoyingly rebuild or verify; just the way of life...
May 29, 2009 8:58:42 PM

Annoyingly rebuilt cost me about 40hr of rebuilding :/ 
And disk check by one non raid disk cost me 4 minutes ...

I could eat it, perhaps by RAID 5 or 10, but by RAID 0 is it a permanent DATA LOS ..

thx for reply btw..
a c 76 G Storage
May 29, 2009 9:23:11 PM

40 hours of rebuilding time is rather long; I assume that it's for several rebuilds.

RAID 0 is fine if one doesn't care about data loss. It's sole purpose is improved speed, not data integrity. I'd use RAID 0 as a system disk only on a test system.
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