On Wed, 31 May 2000, Philippe wrote:
> Hello,
>
> I am looking for high disponibility in a Linux system and was used to use
> a RAID-1 system based on a hardware controller. I am currently working on
> the possibility of using software raid instead, but I am quite in newbie
> with it...
> Could someone explain to me the advantages/disavantages of using software
> instead of harware RAID-1, in terms of security ? Especially is it really
> possible to hotswap a dead disk and to rebuild the array without
> interruption of service ?
> Any hints are welcome.
>
Hardware raid 1 is easier to setup and to handle if a disk fails. With
SW raid you must after you replaced the failed disk, do an fdisk and
then a raidhotadd by hand. However it is possible to hotswap a dead
disk with SW raid without interruption.
I personaly prefer SW raid 1 in conjunction with heartbeat, this means
however that you need two computers. This way however you can take
normal standart hardware (no hotswap disk bays, no expensive hardware
raid controller, etc) and if you wish to upgrade some hardware or
you have to exchange some defective hardware you just switch the services
to the secondary node ie. zero downtime for the outside world.
Holger
