Messages in this thread | | | Date | Wed, 11 Nov 1998 19:13:14 -0800 (PST) | From | David Lang <> | Subject | Re: Linux as a SCSI _Target_ device? |
| |
-----BEGIN PGP SIGNED MESSAGE-----
On Wed, 11 Nov 1998, MOLNAR Ingo wrote:
<SNIP> > On Tue, 10 Nov 1998, Jeff Noxon wrote: > > > Can anyone tell me if it would be possible to make a Linux system appear > > to another system as a SCSI target? I want to RAID 5 a whole mess of > > IDE drives and have it appear to another Linux box as a SCSI hard drive. > > I'm guessing it would be possible with one of the Symbios chips and some > > clever hacking. True/False? Where to start? > > > > If I need special hardware, I'm out. > > i'm not sure wether such a thing exists in retail, but you also need > kernel support for this. The point would be to 'export' a block device > (RAID5) as an SCSI target. >
except for the support for scsi target mode on the controller everything else could be done (a little slower) in user space.
we would need the following
1. configuration/management commands (what are you, reformat yourself, etc)
2. read/write request support, this could simply map a block number (from the host system) to a spot on a local filesystem
putting this in the kernel would be like NFS, a good speed boost, but not nessasary to function.
David Lang
> i was thinking about this one yes, this way Linux could be a real > hardware-RAID box. It's _not_ really complex, but i havent seen this yet. > The board has to do something like this: > > - send an IRQ if an SCSI command arrives > - should be able to DMA out to the SCSI bus and also accept DMA > transfers. > > probably there are some RT considerations (Linux has to react within a > given timeframe), but maybe not, and Linux can sure can do much better > than the millisec-timescale of RAID arrays. It is an interesting project. > True 50-500G hardware-RAID for $5K or so. > > -- mingo > > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.rutgers.edu > Please read the FAQ at http://www.tux.org/lkml/ >
-----BEGIN PGP SIGNATURE----- Version: PGP for Personal Privacy 5.0 Charset: noconv
iQEVAwUBNkpSTT7msCGEppcbAQGtYggAqTEpWu1J2coFcV0iEutD5nq3w7tz5NDN ydyBc6bKUuqJBBAzgFtDfMweZNllueB0r7VfBHVaGHs1bLbuLgvLPF9OhyrAn+Gr MeYFhb0UAh4wcVhsQr0UTd6J7QjZRLuDokpCMF63dxAI6c0xuMA8BwLryCZEjXwA tm2P+oVPu5cLyjCGdSf8T7zI+vzk1PD10bfz5nErK4dNvvOGW8ktQhJ2vvUCBrr8 HOw2IlajERVAnj+0RrzTlEi9CFO7r0NPMGYHgPEAb+ZJ2dB071+6slXjnCkRP0vD ZzybFbt+1sVCZEmW89s2sKRrJRLcMmBwMLs/Zp6GQGmNWnSqwPsfYQ== =jAxa -----END PGP SIGNATURE-----
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |