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I have 16 Seagate Barracuda ES.2 drives in a RAID array. If I select "tags per drive" parameter too high, I get "unexpected drive timeout" across all drives under heavy use. What value should I select for reliable yet fast operation?

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up vote 1 down vote accepted

It is a hardware dependent value, generally 8 seems safe, although 16 seems to be the upper bound on the drives we have.

I have looked at the data sheets and can't see the correct value. If you bought the whole thing as a system then the vendor should be able to supply the correct information

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I came to a similar conclusion. Vendor shipped this unit with 750GB Barracuda ES drives. Unfortunately I did not write down the setting. Now after upgrading to Barracuda ES.2 1000GB drives, I have no idea. Testing shows 4 is OK, 32 is not OK. More on it later in the day. – GregC Jul 21 '09 at 11:26
There is a drive I/O timeout setting. By default it's set to 7.0 seconds. Increasing the "tags per drive" value should be followed with an increased I/O timeout. RAID manufacturer recommends 4 tags per drive for all SATA applications. – GregC Aug 5 '09 at 21:56

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