On Sat 31 Aug 02 16:11, Gene Heskett wrote:
> On Saturday 31 August 2002 07:45, Brian Jonnes wrote:
> >Hi,
> >
> >I think I have a faulty tape or two. What is the best recommended
> > way of testing this? Generate a file from /dev/urandom, write it
> > to the tape and md5sum it?
>
> Most drives do the equ of that themselves. its when they can't
> recover the error that you become aware that its doing re-read
> after re-read and reporting a failure.

Okay, here's the deal. I'll use my DAILY_04 tape as an example. Dump on 13/08:

---
These dumps were to tape DAILY_04.
The next tape Amanda expects to use is: DAILY_05.


STATISTICS:
                          Total       Full      Daily
                        --------   --------   --------
Estimate Time (hrs:min)    0:01
Run Time (hrs:min)         2:46
Dump Time (hrs:min)        1:46       1:20       0:25
Output Size (meg)        3940.3     2940.1     1000.2
Original Size (meg)      6798.4     5010.1     1788.3
Avg Compressed Size (%)    58.0       58.7       55.9   (level:#disks ...)
Filesystems Dumped           27         13         14   (1:8 2:4 3:2)
Avg Dump Rate (k/s)       637.2      626.3      671.6
---

As you can see, the tape was used to the full. Now, on 31/08 I had a 
failure:

---
These dumps were to tape DAILY_04.
*** A TAPE ERROR OCCURRED: [[writing filemark: Input/output error]].
Some dumps may have been left in the holding disk.
Run amflush to flush them to tape.
The next tape Amanda expects to use is: DAILY_05.

FAILURE AND STRANGE DUMP SUMMARY:
  valhalla   /export/mail/pmail.usr lev 0 FAILED [disk /export/mail/pmail.usr 
offline on valhalla?]
  valhalla   /export/mail/subs lev 0 FAILED [out of tape]
---

Now from this I'd assume it was trying to write too much data. But looking at 
the log files, it seems that it only wrote a couple of kb (unfortunately I 
can't access the server right at the mo'). 

Where am I going wrong? Are the logs straightforward to interpret (i.e. I add 
up the kb for the DUMPER lines up until the point of failure)? Can tapes be 
intermittent?

> failed, one of them ripping the tapes in two violently, in less
> than a year.  So generally speaking, TR4's aren't any more, or less
> dependable than a DDS2, but the DDSx format is slowly pulling ahead
> in my personal tally sheets.  Plus the DDS2 tapes are beaucoup
> cheaper...

I have to get a new (and bigger) drive in the near future, so I'll definitely 
look into these.

Regards,

Brian Jonnes
-- 
Init Systems  -  Linux consulting
031 767-0139    082 769-2320    brian AT init.co DOT za