Re: Promise or 3Ware? - booting
On Thu, 25 Mar 2004, Miquel van Smoorenburg wrote:
> The problem with software raid is that if the first (boot) disk
> goes south, the system won't boot anymore. If you're using RAID1
> just for data integrity and don't care if you have to open up the
> machine and replace the disk to get it going again, then that's
> no problem. If you want to maximize uptime, use hardware RAID1/RAID5.
i've not seen sw raid1 preventing a system boot if either/any disks
goes down ...
- just need to config it correctly .. and test it by pulling
the ide cable off of the disk under test
- a properly config'd raid setup should still keep working
even if its in degraded mode
- if you need a keyboard/screen into that raid box, than
why setup raid .. its NOT working
- when it doesnt boot... i'm always curious to see
how /etc/raid[conf] was setup, the partition type
and lilo.conf or grubconf files
- sorta defeats the purpose of raid if it doesnt boot
<chant>
- if one setup any raid .... i assume that there are dire consequences
if the server went down .. vs spending the 15 minutes to just reinstall
debian into another system disk
15 minutes of down time costing gazillion $$$ of loss revenue
vs the days spent to properly config and test the raid system
regularly
- if data is important, you'd better have that important data
on at least 3 different disks, preferably in 3 different
geographically isolated servers
- having data saved to the spare disk on the same server
is worthless as an unfortunate sole just found out recently
when their power supply went bonkers
- and having it in the same bldg ( same circuit ) is equally
bad as there are brown outs and power surges on your ac power
- raid is NOT a reliable data backup
raid1 is the worst for data backup..
( "rm filename.foo" and its gone from the other disk too
( in a matter of seconds
</chant>
> But if you wanted to minimize downtime, you'd have bought hot-swappable
> SATA disks anyway, I guess.
a good experiement to do w/ sata disks
and if you're using hot-swappable ide ... hehehe ... that doesnt work
either
>
> If you're going to do software RAID1 - the latest 2.6.5-rc kernel
> supports partitionable RAID1 so you can just RAID1 2 entire disks
> instead of just the partitions. I've updated sysvinit to work
> correctly on such a system (root partition with dynamic major device).
that sounds like fun ..
> I think I should convert our internal dutch documentation to an
> english MINI-HOWTO one of these days.
whats the url of the dutch version that can be externally accessible ??
collection of docs/scripts for raiding ..
http://www.1u-raid5.net/HowTo
have fun
alvin
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