[CentOS] RAID help

Tue Dec 14 18:49:31 UTC 2010
m.roth at 5-cent.us <m.roth at 5-cent.us>

Hey, Jason,

Jason T. Slack-Moehrle wrote:
>
> I have a new system with 2 Seagate 1TB SATA Enterprise level drives in it.
>
> I want to RAID1 (mirror) these drives.
<snip>
> So if I simplify, I must:
> 1. Create a software raid partition on each drive
> 2. Create a RAID 1 out of that partition and use a mount point of /boot

Only if you want to mirror the boot partition.
>
> 3. Create other mount points I might want i.e swap, /home, etc
> 4. Create RAID1 out of these partitions

Only if you want each directory RAIDed. DO NOT mirror swap. Bad idea.
<snip>
> A few questions:
>
> 1. This system support 16gb of RAM. I have 9gb in it, but I will max it
> out over the next few months as I find great deals on RAM, what should my
> SWAP space be? I recall a long while ago that SWAP should match physical
> RAM.

Nope. Received Wisdom said 2-2.5 times RAM. However, in these days of in
insanely huge amounts of RAM, it's not really important. At work, I just
make swap 2G for everything (and trust me, we've got servers that make
your memory look piddly).
>
> 2. Any reason I can't just create a single mount point taking up the
> entire drive and RAID1 the entire thing? Can anyone recommend some ideal
> mount points and sizes?

Nope, no reason.
>
> 3. What should I account for if my /var/www/html will be very large?

My manager here doesn't like LVM; but if it were me, I'd make that
/var/www an LVM virtual partition. That way, you can always add another
drive and thow more space into it.

       mark