Can anyone tell me what the following command means :
$ mount /disk1 on /dev/md/dsk/d9 nosuid/read/write/largefiles

Thanks alot.

Syntatically this appears to be incorrect - at least I've not seen it written this way:
mount /disk1 on /dev/md/dsk/d9 nosuid/read/write/largefiles

It should be:
mount /dev/md/dsk/d9 /disk1 -o nosuid,read,write,largefiles

Basically it saying ot mount the device called /dev/md/dsk/d9 on the mountpoint (directory) called /disk1. The final things are options for the filesystem. Doing "man mount" would explain what each of the options do.

Note that /dev/md/dsk/d9 would appear to be a metadisk (probably RAID).

Once mounted you can do ls -l /disk1 to see the contents of the mounted filesystem.

Also nothing in what you wrote includes filesystem type which would be specified with the "-t" option. So long as it is a valid filesystem it should be able to mount it without that but just thought I'd mention it.

Most of your predefined mounts should be in /etc/fstab so you can "cat /etc/fstab" to see other examples. "man fstab" will give you info on that file's layout.

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