Re: [Iscsitarget-devel] Re: latest status on support >2Tb device

[Ming Z. <mi...@el...>]

On Thu, 2005-01-27 at 23:14, Ice Cold wrote:
> Ming,
> 
> This might be a dumb question but what is the difference between
> fileio mode and rawio mode.
> 
in iet, we need a way to write/read data to/from device. at the
beginning, we use block device as the storage devices. we use vfs
operation to r/w. see fileio.c. historically, there is also a blockio
mode which operate with bufferhead directly. but that blockio is
unstable and we removed it since fileio performance is good enough.

now we want to support more type of scsi device besides of disk type. my
consideration is to implement a bypass mode that pass all scsi commands
to real scsi device connected. so iet act as a kind of router. so we
call this is a rawio, see target_raw.c for detail.

> Also how are u able to simulate a >2TB volume.
> 
To setup testing 3 TB device just run:
dd if=/dev/zero of=3TB bs=1M count=1 seek=3145727
losetup /dev/loop0 3TB

c&p from previous email from Libor. You can only use xfs to get this big
sparse file. I tried reiserfs and ext3fs, none ok.



> Ritesh
> 
> 
> On Thu, 27 Jan 2005 15:22:58 -0500, Ming Zhang <mi...@el...> wrote:
> > attach one screenshot.
> > 
> > On Thu, 2005-01-27 at 15:20, Ming Zhang wrote:
> > > Hi, folks
> > >
> > > Now I tested my iet code with latest beta version MS ini and ms disk
> > > manager can find >2TB disk. after change the partition format to GPT, it
> > > can partition freely. now the problem is it can not format correctly.
> > > from the trace i do not know why. everything seems normal. This is the
> > > fileio mode.
> > >
> > > I will test the rawio mode later.
> > >
> > > if you have interest, i can give u the code. the code needs to be
> > > refined before trying to merge.
> > >
> > > Ming
> > 
> > 
> >