All of your emails:
Reply-To:       [email protected]

With Apple Mail when I hit Reply, I get your email address only. When I use 
Reply All, I get yours and the list and anyone else put in the cc list. I never 
email people on lists directly myself, I always start with Reply and if that 
only goes to the individual, I hit reply all.

So you're welcome to figure out why you're getting double copies, the problem 
is not on my end.

Chris Murphy


On Mar 9, 2011, at 2:00 PM, objectwerks inc wrote:

> Can you stop sending me double copies of every mail please Chris?  Do you 
> know what REPLY-TO means in the headers?
> 
> 
> On Mar 9, 2011, at 1:56 PM, Chris Murphy wrote:
> 
>> Chad, I am aware of the magnitude of the problem *IF* corruption occurs in 
>> RAID 5. That is not even remotely relevant with a conversation about the 
>> probability of such corruption.
>> 
>> There appear to be two competing claims here:
>> 
>> 1. RAID 5 itself is well known for having silent data corruption and should 
>> not be used.
>> 
>> 2. Apple sold, until very recently a Mac OS X based, hardware RAID 5 
>> solution, supposedly honoring a "do no evil, cause not harm" philosophy.
>> 
>> RAID 5 is not a new thing. Silent data corruption is not a new thing. I 
>> won't buy an argument suggesting Apple just figured this out recently and 
>> that's one of the reasons why they killed the Xserve RAID.
>> 
>> Chris Murphy
>> 
>> On Mar 9, 2011, at 1:51 PM, objectwerks inc wrote:
>> 
>>> 
>>> On Mar 9, 2011, at 1:46 PM, Chris Murphy wrote:
>>> 
>>>> 
>>>> 
>>>> On Mar 9, 2011, at 1:35 PM, objectwerks inc wrote:
>>>> 
>>>>>>> The integrity of the data with files after any issues such as these may 
>>>>>>> be suspect, especially if the fileystem was on a RAID5 which is very 
>>>>>>> well known for silent data corruption. This is why RAID5 should not be 
>>>>>>> used.
>>>>>> 
>>>>>> OK that's possibly a whole separate thread for qualifying such a 
>>>>>> statement. Apple has a supported product that uses RAID 5. I have 
>>>>>> clients with them and they've lost drives, and no data, and no data 
>>>>>> corruption. And an even larger sample size exists if filesystems other 
>>>>>> than jhfs+ are considered. RAID 5/6 are common with ext3, ext4, XFS and 
>>>>>> other file systems without anyone suggesting RAID 5 in particular is 
>>>>>> known for itself increasing the incidence of silent data corruption.
>>>>>> 
>>>>> 
>>>>> 
>>>>> There is a reason why it is called silent data corruption.   They may not 
>>>>> know they have it.  It happens all the time and with HW raid 5 you may 
>>>>> not even know it for a long time.
>>>>> 
>>>>> This is the whole reason why ZFS was made.
>>>> 
>>>> ZFS was not made for combating this claim of RAID 5 specific silent data 
>>>> corruption, but rather silent data corruption in general.
>>> 
>>> And the difference is?   You corrupt one disk in a RAID 5 array and the 
>>> whole array is corrupted.
>>> 
>>>> 
>>>> RAID 5 employs parity. RAID 1 does not, nor do conventional non-arrayed 
>>>> jhfs+ volumes. While RAID parity is not as sophisticated at ZFS 
>>>> checksumming, it is certainly better than nothing. So there is some error 
>>>> detection and correction possible, so I'm not understanding how RAID 5 is 
>>>> "well known for silent data corruption" and should not be used. I think 
>>>> this is a rather remarkable claim.
>>>> 
>>>> 
>>>> Chris Murphy
>>> 
>>> 
>>> If you have one disk that has silent data corruption (and parity may not 
>>> help you at all as you calculate your new parity on the corrupted data) you 
>>> compound it with RAID 5.
>>> 
>>> http://www.raidinc.com/pdf/Silent%20Data%20Corruption%20Whitepaper.pdf
>>> 
>>> 
>>> http://boink.superatomic.com/2009/04/25/the-raid-5-write-hole/
>>> 
>>> 
>>> http://www.google.com/#hl=en&sugexp=ldymls&xhr=t&q=raid+5+silent+data+corruption&cp=24&qe=cmFpZCA1IHNpbGVudCBjb3JydXB0aW9u&qesig=0VyEUZb1ePVXqTxPyJd8vg&pkc=AFgZ2tkTDI1HqM7fc6R1egXasC-1CNF3wT4BG5rzsZmDlr4IGBRuaMW3LWOqaaHzeI1IQlVZ2T5WTE3o3LlGRR6gLiYOy2lsHA&pf=p&sclient=psy&site=&source=hp&aq=0b&aqi=&aql=&oq=raid+5+silent+corruption&pbx=1&bav=on.2,or.&fp=ef34c9a9ed856910
>>> 
>>> 
>>> 
>> 
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> 

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