LVM problem <SOLVED>

[Robin Laing]

Scot L. Harris wrote:
> On Thu, 2005-10-06 at 16:32, Robin Laing wrote:
> 
>>Scot L. Harris wrote:
>>
>>>On Thu, 2005-10-06 at 13:54, Robin Laing wrote:
>>>
>>>
>>>
>>>>200Gb just isn't enough.  I just put in 300 gb and going to add teh 
>>>>old 100G to the LVG to allow for videos and music and data files to be 
>>>>stored.
>>>>
>>>>I was unsure about LVG as I could just mount drives in subdirectories. 
>>>> It was the fact that LVG would allow this to be done transparently 
>>>>is the selling point to me.
>>>>
>>>>I have calculated that I would need about 1TB to do what I want.  I am 
>>>>looking at RAID arrays.
>>>
>>>
>>>Just note that the more drives you add to a logical volume the more
>>>likely it is that that volume will have a failure.  If the data is
>>>critical make sure you have backups or that you are using raid.
>>>
>>>I currently have one file system that is 1TB is size running across four
>>>drives.
>>>
>>>/dev/mapper/VolGroup00-LogVol02        1018G  483G  536G  48% /video
>>>
>>>I accept the fact that if one of the drives fail I will lose data.
>>>
>>
>>This makes an interesting point.
>>
>>I am using mirrored drives now as volumes.  md0 and md1.  If one drive 
>>fails, I wonder how this will be handled.
>>
>>This is so much fun.
> 
> 
> With mirrored drives if one drive fails you are still OK, your data is
> still on the other drive and is accessible.  You just need to replace
> that drive and rebuild the mirror.
> 
> If one of my drives fails in the LVM group that file system on that LVM
> group is gone.  It is important to understand this distinction between
> using LVM and raid.  
> 
> 
> 

I know the difference between the two but I am looking at LVM groups 
made from RAID1 (mdx) drives.  I am assuming and hoping that the RAID 
will protect the LVM as I am not losing the drive but only a copy.

-- 
Robin Laing