Red Hat Bugzilla – Bug 81938
System hangs at end of ide-tape related operations
Last modified: 2005-10-31 17:00:50 EST
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Description of problem:
When I try to use my tape drive (Seagate Travan 10/20GB IDE), I encounter
reproducible system freezes at the end of whatever tape operation is attempted.
For example, restore -t will start the drive in motion, whirr for a bit (as
normal) but then freeze the system solid at the very moment you expect it to
complete. This also happens with tar, cpio but /not/ mt.
I am accessing the drive using the ide-tape module, on /dev/nht0.
This problem did not occur under RedHat 7.1
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1.put tape in drive
Actual Results: System freeze. Requires reboot.
Expected Results: Contents of first file on tape should be listed
System is an Athlong 1.2GHz, with Abit KT7A motherboard (VIA chipset)
Something enabled DMA again, it seems. I thought we fixed that in initscripts?
mt does not transfer data blocks, only commands.
As a workaround "hdparm -d 0 /dev/hdc" should work.
hdparm -d 0 /dev/hdd does indeed work, so this probably is the DMA bug I'd
thought was fixed. Which init script would you recommend putting the hdparm line in?
I forget if RHL8 had multiply /etc/sysconfig/harddisk*, or only "harddisks".
On RHL 9, copy /etc/sysconfig/harddisks into /etc/sysconfig/harddiskhdd
and edit USE_DMA statement. If RHL8 does not support that, add the command
into /etc/rc.d/rc.local. Editing "harddisks" will kill DMA on disks, so
don't do it.
There were some arguments that ide-tape can be fixed for DMA,
unfortunately it seems there is no way to find which tapes were
broken except white/black lists.