[CentOS] Re: software raid

Sat Mar 31 00:43:09 UTC 2007
Feizhou <feizhou at graffiti.net>

>>> There is one advantage of hardware RAID that hasn't been mentioned
>>> yet, and that's hot-swap.  Last time I tried, software RAID fell over
>>> when a HDD suddenly disappeared.
>>>
>> Did you just pull the thing out? I believe there was supposed to be some
>> mark down procedure before you actually pull the disk out.
>>
>>
>> Besides, it sounds weird...isn't the disk disappearing when it dies more
>> or less the same?
>>
>> I will be testing yanking out a drive on my box. I will let you know how
>> it goes.
> It is the breaking of electrical connections that it trips on. Even if a drive
> fails, it is still commected, and the system can ignore it. AFAIR you can't
> hot swap a regular SCSI drive either.
> 

I don't try yanking non hot-swap drives. I watched a guy try to connect 
an IDE cable while the box was on and on his lap. He got an electric 
shock. 8-|

Anyway, a pull power plug and a pull eSATA cable test both resulted in 
the expected degradation of mirror. Plugging in power or eSATA cable and 
then bringing the disk back online worked as expected. Open Solaris 
zpool mirror.

No echo > /proc special knowledge needed either.