Hi, I've found an issue regarding root-lvm, at boot, lvm writes some files in /etc/lvmconf, /etc/lvmtab, /etc/lvmtab.d at boot in initrd and if lvm dont find enough space in ramdisk, it will not be able start up and never get root filesystem mounted... So you need to make a bigger ramdisk for initrd
It's a small summary of the problem case it's 4:00 am in the morning....
Finally, I go a job as a system administrator for a large company with RHEL servers... I've seen a few problems with performance, kernel ops and programs dying with no apparent reason, so I think there should news about fixes or workarounds about it...
I'm currently having issues with IBM SDD (Subsystem Device Drivers) probably due I've not read the complete manual... so expect news in the future
I'm having issues with root in lvm which is not recognized at kernel upgrade...
And many other minor things which could be interesting to digg inside in my free time
Intel pentium 4 has a cpufreq capability (p4-clockmod module) which can lower the frequency of the cpu... but what about using maximum speed when needed?
The kernel has it's own governors named "conservative", "ondemand", "powersave", "userspace" which let you dinamically change the frequency ( modules: cpufreq_conservative, cpufreq_ondemand, cpufreq_powersave, cpufreq_userspace)
cpufrequtils helps in configuring the max/min frequency and governor
cpufreq-info will give you the current governor and frequency without digging in sysfs
cpufreq-set will dinamically let you change the governor
$ cpufreq-set -g [ondemand|performance]
/sys/devices/system/cpu/cpu0/cpufreq/ondemand/ignore_nice_load
devices/system/cpu/cpu0/cpufreq/ondemand/ignore_nice_load = 1
At debian, there is a program named "apt-show-versions" which show the updates available... even tough I've a 2mbit dsl link I usually just upgrade the major/minor updates (no revisions), after having a list of 400 packages to update every 2 weeks and not even use some of them, I decided to give my script power a try... so I create a script to just list to avoid listing the revision updates and I got something like.../usr/bin/apt-show-versions -u | sed -e 's/\([:alpha:]*\) .*from \([0-9]:\)*\([0-9.a-zA-Z~]\+\)\([0-9a-zA-Z.+-]*\)* to \([0-9]:\)*\([0-9.a-zA-Z~]\+\)\([0-9a-zA-Z.+-]*\)*/\1 \3 \6/' | awk '{ if ( $2 != $3 ) print $1, "upgradable from", $2, "to", $3 }'
looks like hell but works, so use it if you like...
I not a fan of 64-bit technology, besides at work we have 4 64-bit hosts and only two of them have a 64-bit OS... which both have vmware gsx...
As a sysadmin I need automation and vmware use a perl tool called vmware-cmd with 32bit library dependency. 64-bit host is not supported according with this official document and is a known issue which will probaby not be resolved cause gsx is to be replaced with vmware server and other technologies, besides vmware states that 64bit support is experimental for gsx
After being disappointing by the fact, I decided to use the gnu/linux power and looked for a hack in vmware forums and the procedure is the following...
Copy library and perl32 binary from 32bits-host to 64bits-hosthost32# scp -rv /usr/lib/perl5/5.8.5/i386-linux-thread-multi host64:/usr/lib/perl5/5.8.5
host32# scp -r /usr/lib/perl5/site_perl/5.8.5/i386-linux-thread-multi host64:/usr/lib/perl5/site_perl/5.8.5
host32# scp /usr/bin/perl host64:/usr/bin/perl32
Edit /usr/bin/vmware-cmd to use perl32 and libraries< #!/usr/bin/perl -w -Iblib/arch -Iblib/lib -I/usr/lib/perl5/5.6.0/i386-linux -I/usr/lib/perl5/5.6.0 -I. --- > #!/usr/bin/perl32 -w -Iblib/arch -Iblib/lib -I/usr/lib/perl5/5.6.0/i386-linux -I/usr/lib/perl5/5.8.5 -I/usr/lib/vmware/perl5/site_perl/5.005/i386-linux -I.
Not too difficult considering that almost give up when I saw there was not support for 64-bit host
