Which RAID

[kau]

I am setting up two servers. What RAID should I go with for my DB server? I have up to four drives I can use that are all the same. It's an Opteron with 4 gigs of RAM.

[eva2000]

what type and speed of drives ?

best for db would be 4x or 6x scsi 15,000rpm raid 10 with PCI-X 64bit/133mhz supported hardware controller with onboard processor and memory cache 128-256MB on a PCI-X 64bit/133mhz slot

if you have a vB database well over 4GB in size where postindex/word tables are huge might set up a 2nd array for raid 0 and place postindex/word tables on the raid 0 array and symlink it back to the data directory for mysql

for those on a very cheap budget maybe 4x 80GB Hitachi 7K80 SATAII NCQ drives or 74GB Western Digital Raptor SATAs (more expensive) on a PCI-X 64bit/133mhz hardware raid controller ideally Areca branded ones but promise, adaptec and 3ware are other brands

[kau]

These are the servers ...

[kerplunk]

You really should have went SCSI for the servers (or at least the database server).


RAID 10, either way.

[kau]

With RAID 10 and 4 hard drives. How many HD can I lose, as in they burn out, and still be in the clear in regards to keeping my data intact.

[eva2000]

http://www.raid.com/04_01_10.html full info

[kau]

That doesn't list how many drives I can lose before I have a problem with RAID10

[kau]

Also what OS should I run. I was thinking Fedora or Suse. Are both those the same pretty much?

[eva2000]

it ain't hard to find raid 10 info = google.com ;)

http://en.wikipedia.org/wiki/Redundant_array_of_independent_disks#RAID_10

All but one drive from each RAID 1 set could fail without damaging the data. However, if the failed drive is not replaced, the single working hard drive in the set then becomes a single point of failure for the entire array. If that single hard drive then fails, all data stored in the entire array is lost.

Extra 120GB hard drives could be added to any one of the level 1 arrays to provide extra redundancy. Unlike RAID 0+1, all the "sub-arrays" do not have to be upgraded simultaneously.

RAID 10 is often the primary choice for high-load databases, because the lack of parity to calculate gives it faster write speeds.

RAID 10 Capacity: (Size of Smallest Drive) * (Even Number of Drives ) / 2 so for 4x hdd raid 10 you can afford to loose 1 hdd from each raid 1 segment so you can afford to loose 2 drives and still have data intact



as to OS Suse 64bit enterprise linux probably be better if you want 64bit OS

[kerplunk]

That doesn't list how many drives I can lose before I have a problem with RAID10
RAID 10 allows you to lose one hard drive, and in some circumstances you can lose two.

Use Fedora.