Difference DSK RDSK

Applications Filesystems, Disks and Memory
1

COuld you please telle me the diffrence between DSK and RDSK with exemple if possible...
Thanks a lot in advance.
Regards.

2

DSK is a block device path for Ex; /dev/dsk RDSK is a raw device path /dev/rdsk those are the standard solaris filesystem. Is this what you are looking for..?

3

When a process sends requests to a rdsk type special file, it is talking directly to the driver. A read or a write goes directly to or from device. Reads and writes must be aligned on DEV_BSIZE boundaries or the results are undefined.

When a process sends requests to a dsk type special file, it is talking to high level os routines. A read or write goes to or from the buffer cache. If needed, the os will read new data into the buffer cache. There are no alignment restrictions. You can read or write any collection of bytes anywhere on the device. The os will send aligned requests to the driver, but this is hidden from the process. I/O requests that arise from accesses to a dsk type special file enter the driver via its strategy entry point, not the read and write entry points. The driver may resequence the requests to optimize overall performance.

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4

Ok thanks for your help but from a point of view, what can be a few simple words to explain (non technicly) the difference ...

Regards

5

Ummm...that was the simple explanation.

The difference between and dsk and rdsk is a technical subject. There is no way to explain the difference non technically.

6

ok thanks again for the explanation ...
If someone could tell me concernign dsk and rdsk something more technical (or an url to read...) That could be clear to understand for exemple :
1) what means the dsk and rdsk directory ?
2) how are they usefull to administrate a machine ?
3) how using the for an administrator ?

Thanks a lot in advance.
Regards.

7

I had the same question and found this link while searching for an answer.

http://www.idevelopment.info/data/Unix/Solaris/SOLARIS_UnderstandingDiskDeviceFiles.shtml

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8

@PREDERABO

Nice answer It really helped me though ..... for those who did not understood ...... when u look at the contents of rdsk and dsk they are the same but the difference is in the way and where they operate .... like rdsk will directly operate on the driver tht's more of the hardware side while dsk will operate on the processes more of the software side .... if thr's any error in my answer plz do reply :slight_smile: