This morning I came in to find our backup job stalled. Abortjob was ineffective, as was abortio. I ended up rebooting the system. While coming up, I got the “defective sector” message with “FILE.GROUP.ACCOUNT has an extent with unreadable data.” The file is now locked and I need to use FSCHECK to unlock it. How can I determine which drive this extent is on? I have a good idea which one it is, but I’d like to be 100 percent sure before I replace and reload.
Stan Sieler replies:
FSCHECK’s DISPLAYEXTENTS command may help. Note that, if I recall correctly, it displays logical unit numbers, not exactly LDEVs.
I ran checkslt on the MPE/iX 7.5 SLT and it failed. It failed on a DDS-2 drive on two different systems but passed when a DDS-3 drive was used. The MPE/iX 7.5 SLT is on a 120-meter DDS-2 tape. Is this usual?
Michael Berkowitz replies:
What makes you think you don’t have two bad DDS-2 drives? When we had them, we went through them like water, replacing them every couple of months. They are bad news from the word go.
But how can I have two bad DDS-2 drives?
Gilles Schipper notes:
Not surprising at all. I once experienced the following situation. Our customer had a disk crash. Fortunately, it happened just after a full backup. HP replaced the faulty disk drive and we proceeded to perform a system reload from the just-completed backup that had been to a DDS-2 tape drive.
As soon as we mounted the tape (on exactly the same tape drive that created it), we received a console message indicating AVR error on LDEV 7. I knew right away we had a problem. HP returned to replace the tape drive with another DDS-2 drive. Still no joy. We recommended replacing the drive with a DDS-3 tape drive. As soon as this was done, the reload proceeded without further problems.
The bottom line is stay away from DDS-2 drives, as far away as possible. From this experience and others, I have concluded that the DDS-2 drive is, to put it mildly, flaky.