Nico Morrison
2003-Feb-06 10:07 UTC
MORE: On very different journalling activity on 2 servers.
At first our datacentre techies thought that lilo was forcing the old kernel. They altered lilo.conf & rebooted. It now seems that although the grub config file shows all 3 kernels & the newest is the default - when the system reboots - only the oldest kernel shows on the GRUB screen & only the oldest kernel boots! What can we do to get the newest kernel to boot instead? Regards, Nico Morrison nico.morrison@micronicos.com ___________________________________________ Micronicos Limited - London, UK. Tel: +44 20 8870 8849 Fax: +44 20 8870 5290 ___________________________________________ Hello, I have upgraded the 'bad' machine with the latest 'up2date' kernel, but it is possible that GRUB is still loading the older kernel. Our sysadmin at the dayacentre says the console shows the old kernel kernel-2.4.7-10 This might have happened because the first kernel upgrade I did on this machine I did manually by downloading the .rpm & installing it locally. Now I know to use /use/sbin/up2date instead but ...... How do I tell from the machine (SSH) which kernel it is actually running? Thanks - sorry to be so ignorant. Regards, Nico Morrison nico.morrison@micronicos.com ___________________________________________ Micronicos Limited - London, UK. Tel: +44 20 8870 8849 Fax: +44 20 8870 5290 ___________________________________________ From: Stephen C. Tweedie [mailto:sct@redhat.com] Sent: 05 February 2003 10:13 To: Nico Morrison Cc: 'Andrew Morton'; ext3 users list Subject: RE: On very different journalling activity on 2 servers. Hi, On Wed, 2003-02-05 at 08:45, Nico Morrison wrote:> [root@ns5 nico]# /sbin/hdparm /dev/hda > /dev/hda: > using_dma = 0 (off)> Does this mean that dma is in fact off?Yes.> Looks like is ON on the server that has no problems and OFF on the onewith> loadsa journalling?Yes.> What do we need to do & is it safe to turn DMA ON on a busy working public > internet server?You don't. The trouble is, the kernel usually has a reason for not being in DMA mode. If it can negotiate DMA, it will; but the older of your two systems did not do so, so either that older kernel doesn't know how to drive the IDE controller in DMA mode safely, or it has detected an error on the IDE bus and has backed off to non-DMA mode automatically. In both cases, forcing DMA on manually is not recommended. I'd suggest that you upgrade the 7.2 box to the current errata kernel, which is the same across all the 7.* releases. That should give you the same updated IDE drivers as the 7.3 box has, and will hopefully get you running DMA properly. If it doesn't, then you're going to have to check the logs to see why DMA isn't being negotiated. Cheers, Stephen