NAME
fs – file system devices |
SYNOPSIS
bind –b #k /dev /dev/fs /dev/fs/ctl /dev/fs/... /dev/new |
DESCRIPTION
The fs driver builds complex disk files out of simpler disk files.
Inspired by the Plan 9 file server kernel's configuration strings,
it provides device mirroring, partitioning, interleaving, and
catenation for disk–based services like fossil(4) or venti(8).
The device is intended to be bound at /dev and initially contains a directory named fs, which in turn contains a ctl file and one file per configured device. Most control messages introduce a new device, here named new. The file arguments are interpreted in the name space of the writing process.
The device name new may be a single filename component (containing
no slashes); in this case, the device is created under #k/fs.
If new instead has the format dir/file, the device is made available
at #k/dir/file. The directory dir goes away when the last device
on it is removed with the del control message, but
#k/fs will never be removed.
part new offset end
disk dir [ n file ]
If the variable fsconfig is set in plan9.ini(8), fs will read
its configuration from the file $fsconfig on the first attach.
This is useful when the machine boots from a local file server
that uses fs. |
EXAMPLES
Use a previously partitioned disk, /dev/sdC0, making partition
files available under /dev/sdC0parts:
|
SEE ALSO
read in cat(1), dd(1), sd(3), fossil(4), fs(8), plan9.ini(8),
prep(8), venti(8) |
SOURCE
/sys/src/9/port/devfs.c |
BUGS
Mirrors are RAID–like but not RAID. There is no fancy recovery
mechanism and no automatic initial copying from a master drive
to its mirror drives.
Each write system call on ctl may transmit at most one command. |