Unix Users Meeting

April 29, 2003

90rolling

• RedHat released RedHat 9.0 on April 7, 2003

• We expect to have the first 90rolling (Development) release out 2 weeks later which would be April 21,2003

  • We released the first 90rolling on April 7, 2003 5 hours after Redhat's release

    • openafs

    • Fermi openssh

    • Full Fermi Kerberos support

    • YUM auto updates for security errata

    • UPS/UPS bootstrap with core fue

  • We released first beta with workgroup support on April 21, 2003

• What is left to do

  • upgrades, now we only suport new installs

  • Better install screen, one that is not as confusing

  • bug fixes

  • other things that I forgot

  • more documentation

Fermi Linux 71rolling --> soon to be 712

Please test, expect to make this 712 in a few weeks

Tech Tips

RedHat turned off DMA for cdrom type devices starting with the 2.4.18-? kernels. This was done because many older cdrom drives did not work well with DMA on. Since RedHat could not tell if a drive was ok or not they took the conservative approach and just turned it off.

Reading cdrom would be slower. But most of the time you do not really care about how fast your cdrom is reading.

Writing cdr would be slower. You care a lot about this as if the data is not given to the cdr fast enough you end up with a coaster. The newer drives have a option that you can turn on that helps with this , as you might not get a coaster, but it is still slower. This is the driveropts=burnfree option of cdrecord.

We can see how fast the cdr drive is burning by using the -v option of cdrecord.

So to fix this we need to turn on DMA for the cdrom/cdr in question. First you need to determine which drive it is, we need to know which hd? . You can do this by either looking in /var/log/messages and looking for you cdrom or looking in /proc/ide/hd[abcd..]/model . You could also look in /etc/lilo.conf or /boot/grub/grub.conf to see what drives have ide-scsi enabled. Once you have determined what drive the cdr is on then you can verify that it is off with a hdparm /dev/<drivename>.

Now that we have what drive it is we need to copy /etc/sysconfig/harddisks as /etc/sysconfig/harddisk<drivename>. So since the cdrom is commonly /dev/hdc then this would be /etc/sysconfig/harddiskhdc . Now we need to turn on DMA for this entry. This is done by editing the /etc/sysconfig/harddisk<drivename> file that we just copied. We need to uncomment the USE_DMA=1 line which is near the beginning of the file. This will enable dma for the <drivename> drive on the next reboot. So you can either reboot to enable it or just type in hdparm -d1 /dev/<drivename>, in our example this would be hdparm -d1 /dev/hdc .