Ian Forde wrote:
On Sat, 2009-02-21 at 18:09 -0600, Les Mikesell wrote:
Yes, but raid1 in software has none of those problems, since as far as the boot loader is concerned, you are booting from a single drive. And there is a trade-off in complexity, since sw raid works the same on Linux across different hardware and you need to round up different vendors instructions and utilities for hardware raid - and have a backup controller around for recovery.
RAID in software, whether RAID1 or RAID5/6, always has manual steps involved in recovery.
Don't forget that 'recovery' sometimes means taking the still-working drives and moving them to a new chassis.
If one is using standardized hardware, such as HP DL-x80 hardware or Dell x950 boxes, HW RAID obviates the need for a "recovery procedure".
As long as you have an exactly-matching chassis/motherboard/controller to move to.
It's just easier. You can still boot from a single drive, since that's what the bootloader sees. There are no vendor instructions or utilities needed for recovery. Nor is there a backup controller needed.
Everything breaks eventually. If yours hasn't yet, good luck with that.
The *only* time I'd use software RAID on Linux is if I didn't have a standard hardware base that supported hotswap and commandless recovery, which in any enterprise within which I were to be employed, I'd insist upon (and deploy)...
You can have hot spares in software raid if you can't be bothered to type 'mdadm --add ....' once every few years.