[ILUG] Why RAID

[Gareth Eason]

       Hi,

    Since it's NOT a production environment, and cost is an issue, I 
would consider dropping the hot spare. If a drive does go, you'll fail 
over and lose resilience - but that should be enough to leep you going 
until you get a chance to acquire and install a new drive and rebuild 
your resilience.

    I wouldn't dream of removing the hot-spare from a production system, 
or from a 'difficult to physically access' system (colo box or similar) 
- but with it running at home it's just eating into the MTBF of your 
hot-spare and providing a secondary layer of resilience which you'll 
probably never ever need to use. I'm sure you can think of a good use to 
put the money saved from that drive to ;-)

    RAID1 for the operating system might not be a bad idea. More than 
one person I know has been caught out because they 'forgot' that without 
their raid configuration they were unable to access their data, even 
though it was safely just sitting there in a fully operatinal RAID 
array... Moral: Make sure you have a couple of backups of your RAID 
drivers and your RAID configuration :-)

    Also, if you're building up your aray over time, RAID4 is 
expandable, RAID5 is not (AFAIK) without destroying the data and 
restriping across all the drives. ext3 with RAID4 fully supports dynamic 
addition of partitions to an array.

    Best regards,
    -->Gar



John Coleman wrote:

>[munch...]
>
>I will eventually fill the card with 6 of the drives, but at the
>moment I'm unsure if I should go for 5x raid5 disks + 1x hot-spare or
>what.
>[munch...]
>  
>