[ale] new to raiding

[Jeff Hubbs]

Yeah, definitely make a backup that gets taken away from the house after 
it's made, even if you do RAID.  RAID won't stop a poorly placed rm -Rf.

- Jeff

Denny Chambers wrote:

> Cade Thacker wrote:
> 
>>Hi Ho,
>>
>>I have mirrored two 1 gig drives at /home and my wife, via samba, is
>>saving her Grad school papers onto that share.
>>
>>So my question is,
>>
>>1) how bomb proof is that mirroring.
>>
> 
> Well the Titanic is not unsinkable, but you should be pretty safe. If
> you want addition protection, look into adding a journeling file system
> like xfs, ext3, or rieserfs. Do regular backups!! Just because you
> mirror the drive doesn't mean you should not back it up as well. Make
> sure your mirrored drives are on different ide controllers, so that loss
> of a ribbon cable or ide channel doesn't take both drives down. 
> 
>>2) should a drive go down what happens.
>>
>>From a user perspective nothing. Your not talking to the hard drives
> anymore. Your talking to a single abstract device (md0, md1, etc). The
> abstract device is talking to your two drives. So even if you lose a
> hard drive, as a user all you know about is this md device that your
> talking to. As long as 1 hard drive is working the md device will keep
> working.  You will need to monitor the raid device from time to time
> (cat /proc/mdstat) to make sure that the raid is still happy, and watch
> you syslog files.
> 
>>3) how do I replace a drive, will it automagically pick it up, and bring
>>it up to speed?
>>
> No, not that I recall. I think you will need to manually create a
> partition on the drive that is the same size or larger than the
> partition that you are trying to mirror, then you will need to do
> raidhotadd of the partition back into the raid set. Then the mirror will
> sink back up.  
> 
>>4) Can I boot with a mirrored drive unplugged?
>>
> Sure! Just as long as your boot partition is not on the unplugged drive.
> The md device will just come up in a de-graded mode, which for a mirror
> is not very de-graded as far as performance is goes (No more overhead
> having to write to two drives), but you will not have you mirrored
> protection.
> 
> hope this helps,
> Denny
> 
>>Thanks in advance.
>>
>>--cade
>>
>>==========
>>Yoda: "Luke...I am your father"
>>Luke: "huh?"
>>=========
>>
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> 




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