RAID question

[Niel Drummond]

fairly new to RAID, so forgive my ignorance: I wish to setup two hard
drives with a level 1 RAID scenario for a web server. I can't afford to go
the extra length for a level 5 or 1/0 solution, so I've decided to buy a
fast serial ATA drive, and combine it with a spare IDE drive. Using level
1 RAID, can I use the old (slower) drive to contain all redundancy data
and leave the new (fast) drive as the "active" drive, to avoid any
performance lost from reading data ? Or does RAID 1 read data equally
among both drives ?

I have also read on tomshardware (a curse on those ads)

http://www6.tomshardware.com/storage/20030620/index.html

of a custom 1.5 level RAID implementation using a specific DFI
motherboard. Has anyone had any experience with this?

regards,

- n

 

[Arno Wagner]

fairly new to RAID, so forgive my ignorance: I wish to setup two hard
drives with a level 1 RAID scenario for a web server. I can't afford to go
the extra length for a level 5 or 1/0 solution, so I've decided to buy a
fast serial ATA drive, and combine it with a spare IDE drive. Using level
1 RAID, can I use the old (slower) drive to contain all redundancy data
and leave the new (fast) drive as the "active" drive, to avoid any
performance lost from reading data ? Or does RAID 1 read data equally
among both drives ?

It writes to both drives equally. It reads with some load
balancing, so the IDE will slow things down. It is not like
one drive is the redundancy, it is that both are used as
mirrors in a mostly symmetric fashion.

I have also read on tomshardware (a curse on those ads)

of a custom 1.5 level RAID implementation using a specific DFI
motherboard. Has anyone had any experience with this?

Has the disadvantage that if the board dies your data becomes
unaccessible. If you do the sensible thing and use Linux for the
server, you can use software RAID. It gives pretty good
performance and runs stable with the latest 2.4 kernels.

As for server speed, buy as much memory as possible. HDD
speed is not that important, unless you buy a 15000rpm
SCSI disk. The IDE/SATA disks are really slow compared to fast
SCSI drives.

Regards,
Arno

 

[Michael Hawes]

fairly new to RAID, so forgive my ignorance: I wish to setup two hard

drives with a level 1 RAID scenario for a web server. I can't afford to go
the extra length for a level 5 or 1/0 solution, so I've decided to buy a
fast serial ATA drive, and combine it with a spare IDE drive. Using level
1 RAID, can I use the old (slower) drive to contain all redundancy data
and leave the new (fast) drive as the "active" drive, to avoid any
performance lost from reading data ? Or does RAID 1 read data equally
among both drives ?

Raid 1 is also called 'Mirroring' because you need two drives of the
same capacity and the data is duplicated on both drives. If one drive fails
the system carries on working using the good drive. When you replace the
faulty drive the raid system copies the data ont the new drive to recreat
the mirror set. If you had a 20GB and a 40GB you could create a Raid 1 of 20
GB and a standard 20 Gb on the second part of the 40Gb.
Try Google on 'raid 1' for much more info.

Mike.