glance plus & tape i/o

[Satish Y]

Hi Experts,

I have a query that how can we see Tape I/O using glance plus(like Disk I/O).
Is there any way to configure main window of glance plus to show tape I/O?.

Any advices are encouraged.

Thanks in advance.

Cheers...
Satish.

[John Palmer]

Hi,

If there is, I've never found it. However, you can estimate the tape I/O rate (if it's a backup utility) by how fast your utility is getting data from disk.

Don't forget that the tape drive will almost certainly be doing compression so the actual rate that data is written to the tape will be much less than the rate at which it's being sent to the drive.

Regards,
John

[Satish Y]

John,
We r not reading from disk but reading from the tape(restoring) to disk, reading tape is still in progress, not yet started writing disk.

When we see Disk I/O window, it is showing all h/w addr for disks, not tapes.

Cheers...
Satish.

[John Palmer]

Again, depending on the utility, it may not actually be reading the tape but skipping through file marks (frecover does this).

What utility are you using?

[Frank Slootweg]

As far as I know, tape I/O is not specifically reported by Glance. However you can see the 'file' activity of a process and device files are also files, so you can see device file activity and hence tape I/O activity.

How? Select the process with "Select Process" and then select "Open Files". The "Offset" is normally the amount of bytes read/written.

[harry d brown jr]

In glance (gpm), drill into the process (process resources), then from reports: select "system calls", then from that window open "process open files".

Remember to disable all filters and select as many metrics as you need.
Then using the "file offset" from the "open files" window, and the "elapsed time" in the "process system calls", you can determine the through put.

live free or die
harry

[Tim D Fulford]

# fuser -c /dev/rmt/0m
# glance -F

look at offset

I do not know of a way of doing it like disks where you can go glance -u etc.

Tim