On Tue, 2001-12-04 at 11:10, Ralf G. R. Bergs wrote:
> On Tue, 4 Dec 2001 17:45:35 +0100 (CET), Roy Sigurd Karlsbakk wrote:
>
> >I'm trying to make a real-time filesystem
>
> This is from http://oss.sgi.com/projects/xfs/102_caveats.html
>
> > Realtime volumes not implemented
> >
> > Realtime volumes are not yet tested in XFS Linux and should not be used.
>
> I guess that pretty much says it all... :-)
Except that I am not convinced the caveats page is right in this
respect. To make a realtime fs you will need two partitions, mkfs
will need to be told about the data and realtime partitions, and
mount will also need to be told about them.
mkfs -t xfs -r rtdev=/dev/hdb1 /dev/hda1
mount -t xfs -o rtdev=/dev/hdb1 /dev/hda1 /xfs
You also need special ioctl calls to mark a file as realtime before it
will place data into the realtime subvolume:
XFS_IOC_FSSETXATTR
This takes struct fsxattr as the argument:
struct fsxattr {
__u32 fsx_xflags; /* xflags field value (get/set)
*/
__u32 fsx_extsize; /* extsize field value
(get/set)*/
__u32 fsx_nextents; /* nextents field value (get)
*/
unsigned char fsx_pad[16];
};
You need to set the flag XFS_XFLAG_REALTIME in the fsx_xflags field, and
specify the size of realtime extent you want by default in the extsize
field.
Steve
p.s. I have not tried this recently - but it has worked in the past.
>
>
>
> --
> Verkaufe Original-BMW-Raeder: L I N U X .~.
> http://adsl-bergs.rz.rwth-aachen.de/~rabe The Choice /V\
> of a GNU /( )\
> Generation ^^-^^
>
--
Steve Lord voice: +1-651-683-3511
Principal Engineer, Filesystem Software email: lord@xxxxxxx
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