How do you monitor the performance of a character device (e.g. tape drive)?

Question

There are many ways to monitor block device performance: dstat and iostat, heck, even sar will give you data on block device I/O rates. Unfortunately, I don't know of any good spur-of-the-moment tools for monitoring the performance of a character device like a tape drive.

I know there are tools to monitor performance if you remember in advance to do it (pv, dd + SIGUSR1, probably others), but say you're 2 hours into a job that might be 3 hours or 30 hours depending on the performance, and you don't know which it is.

The only thing I can think of is some elaborate use of strace or similar, parsing the output for bytes written, maybe with timestamps. Is there a commonly used tool that I've forgotten or never heard of?

Have you checked if the device offers ay stats via SNMP? – Sameer May 14 '11 at 06:01 — Sameer, May 14 '11 at 06:01

score 2 · Accepted Answer · answered May 14 '11 at 20:44

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I found a SystemTAP script for SCSI tape devices:

http://sourceware.org/systemtap/wiki/WSiostatSCSI

I haven't tried it; don't know what kind of shape it's in.

answered May 14 '11 at 20:44

rakslice

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This looks very nice; I've been wanting to learn more about SystemTAP. – Slartibartfast May 16 '11 at 04:43
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Just listing the name of another unteseted tool is not a very useful answer. We all have search engines. – Shaun Dewberry Apr 04 '14 at 10:09

score 1 · Answer 2 · answered May 14 '11 at 22:53

As I know, HP has a program which can check HP tape device's performance. You can find it on here

I guess other tape device vendors also have similar tools for monitoring tape device's real time status. You can check their website for this kind of applications. Good luck.

How do you monitor the performance of a character device (e.g. tape drive)?

2 Answers2