Invisible wrote:
> 
> Does anybody actually use RAID on a home system?

Yes.

These
aero@grunka ~ $ dmesg|grep 7\:\ ST37
[    6.425893] ata2.00: ATA-7: ST3750640AS, 3.AAK, max UDMA/133
[    7.613720] ata4.00: ATA-7: ST3750640AS, 3.AAK, max UDMA/133
[    8.198858] ata5.00: ATA-7: ST3750640AS, 3.AAK, max UDMA/133
[    8.783579] ata6.00: ATA-7: ST3750640AS, 3.AAK, max UDMA/133
4pcs of 750G Barracudas give me this:
aero@grunka ~ $ df -h|grep md5
/dev/md5              2.1T  451G  1.7T  22% /home

That's RAID-5 -array, so it can handle a break-up on any of those disks.

These are RAID-1:
aero@grunka ~ $ df -h|egrep 'md0|md2'
/dev/md0               84G   20G   65G  24% /
/dev/md2               88G   22G   67G  25% /netroot

And so are these:
garmaugh ~ # df -h|grep md
/dev/md/0             962M  179M  734M  20% /
/dev/md/2             9.2G  2.1G  6.7G  24% /usr
/dev/md/3              13G  708M   12G   6% /var


> My dad is the only person I know who's tried it, and he has lost far 
> more data due to RAID glitches than to any physical hardware failure!

I've also lost some data due to my own stupidity with RAID. OTOH, I've 
saved at least 5 times that amount of data from disk breaks with RAID.

> have to tell it to rebuilt the array (BE CAREFUL TO SELECT THE RIGHT 
> SOURCE DRIVE!) 

I too can tell you that :). That's the way I erased one array - I synced 
the empty disk over a fuller one.

> and wait many, many hours for that to complete. And then 
> it would work for another few hours before failing one of the drives again.

Freaking slow, if RAID-1 takes many, many hours. That 2-terabyte array 
took some hours and it's RAID-5, so the computer had to calculate all 
the data. RAID-1 is "only" reading and writing and it's much faster.

> In summary, it was hopeless and an utter waste of time.

In summary, he did it wrong ;).

>> Yep, that's true and very reasonable. You should also RAID the 
>> work-partition and take scheduled backups ;).
> 
> Backup onto *what*?

Ie. on external HD?

> I have, like, 100 GB of data now. I'm not aware of anything large enough 
> to hold that other than another HD. (Or an LTO tape...)

Surf man, surf.
http://www.ebuyer.com/product/143877

Smaller ones are cheaper:
http://www.ebuyer.com/product/128601

Plug it in, sync it (ie. with rsync oslt) and plug it out. Or buy 2 of 
them, schedule a sync for every night and manually change the cable to 
another drive every day (this is because offline backups are freaking 
good idea).

-- 
Eero "Aero" Ahonen
    http://www.zbxt.net
       aer### [at] removethiszbxtnetinvalid

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