From: Lee W <centos-list@xxxxxxxxxxxxxxxx>
> Thanks for the heads up
See my (now dated) "Dissecting ATA RAID Options" article in SysAdmin 2004 April.
It covers 4 approaches to ATA RAID:
- OS LVM (software)
- FRAID (software)
- microcontroller+DRAM (hardware)
- ASIC+SRAM (hardware)
> No, just another toy to play with. I'm currently looking a playing with
> Software RAID but would like to have H/W as well.
The only time I implement RAID-5 is for lots of reads.
E.g., a MySQL server on the Internet.
I prefer RAID-0+1 for most operations -- definitely system disks.
RAID-3 is nice for desktop data and single user operations.**
RAID-4 is best for NFS server and large file transfer servers (A/V).
If I'm mega-anal on performance, I'll use multiple hardware RAID-0+1
cards on different PCI-X channels and volumes with a spanned RAID-0
LVM/LVM2 software volume across them.
I would kill to have a HP DL585 with (3) Escalade 8506 cards, one
on their own PCI-X channel, plus a 10GbE on the final PCI-X channel.
[ **NOTE: For 32/64-bit I/O desktops, NetCell's 3 or 5-disc "RAID-XL"
is actually the most ideal design I've ever seen. Instead of striped
blocks, you have parallel reads/writes. ]
> I'm certainly liking what I have seen of the 3Ware card's so far.
Stock kernel support since version 2.2.15 (that's 2._2_ ;-).
It's nice to be able to move volumes from older cards to newer ones
without issue as well.
> Their site lists quite a few distros as supported, including RHEL 3 which
> from a simplistic guess would also mean that Centos 3 (and possibly 4)
> would also be supported.
Been using them in servers since Red Hat Linux 5.2. The drivers for most
microcontroller or ASIC-driven hardware RAID are rather simplistic, because
all the "intelligence" is on-board the card itself.
3Ware's 3DM/3DM2 management suite is a nice addition, although there
have been some SCSI IOCTL changes that are rendering the older
Escalade 6000 as deprecated.
--
Bryan J. Smith mailto:b.j.smith@xxxxxxxx
