[NTLUG:Discuss] RE: true hardware/intelligent ATA RAID -- FRAID cards can get good desktop performance

[Kipton Moravec]

If the system is only for backup, why bother with RAID at all?  Just 
compress and store.

If the issue is hot swappability, then go with USB Drives.

I like to keep it simple.

Kip

At 11:07 AM 7/22/04, you wrote:
>----- Original Message -----
>From: "Bryan J. Smith" <b.j.smith at ieee.org>
>
> > And if you do lots of writes, _never_ do FRAID/software RAID-5.
> > RAIDCore likes to show off its _read_ RAID-5 performance (which is like
> > RAID-0 minus 1 disk at reads), but you _kill_ your systems
> > CPU-memory-I/O interconnect with 3x+ the traffic.  It's not just the
> > XORs, but the fact that you must copy _all_ data into the main CPU
> > to calculate the XORs -- that's just killer, especially as you add
> > more and more disks!
> >
> > It's far, far better to do RAID-5 with an intelligent RAID controller.
> > You push the same amount of data into I/O like it wasn't RAID at all.
>
>OK...so what I'm reading is NO SOFTWARE RAID-5.  .....BUT.!...
>What if the server's entire roll in life is to be a backup server?  In lieu
>of swapping tapes, I was hoping to swap several  four disk raid-5 sets.
>Once I install the RAIDTAB file as a persistant superblock, those four
>disks would be forever married and handled beautifully.  If I put in a
>hardware RAID card, how will the system handle the swapping of
>different 'backup-sets' (of drives)?
>
>Wait a minute.....I don't need to do raid-5 for this.  I can just do
>RAID-0 and stripe the data across three disks with no  redundancy.
>They are just glorified backup drives anyway. Three 250Gig ide drives
>in scsi trays = 750Gig of backup storage.  Speed isn't necessarily the
>issue...the Gigabit backbone is going to be the limiting factor anyway.
>
>I do need to take a look at the 3ware controllers..but I need to make
>sure that the ide drives can be hot-swapped.  I have to say that I'm
>concerned that using a hardware controller for my specific task might
>limit the application of solution creativity to my particular problem.
>
>Off to do more reading.  Thanks guys.
>
>--
>Richard
>
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