gem

Current version:
# gem search -r rails | grep -E "^rails "
rails (3.0.8)

Previous version:
# gem search -r rails --pre | grep -E "^rails "
rails (3.1.0.rc4, 3.1.0.rc3, 3.1.0.rc2, 3.1.0.rc1, 3.1.0.beta1, 3.0.9.rc3, 3.0.9.rc1, 3.0.8.rc4, 3.0.8.rc2, 3.0.8.rc1, 3.0.7.rc2, 3.0.7.rc1, 3.0.6.rc2, 3.0.6.rc1, 3.0.5.rc1, 3.0.4.rc1, 3.0.0.rc2, 3.0.0.rc, 3.0.0.beta4, 3.0.0.beta3, 3.0.0.beta2, 3.0.0.beta, 2.3.9.pre, 2.3.8.pre1)

Linux Bridge

http://www.linuxfoundation.org/collaborate/workgroups/networking/bridge#Bridging_and_Firewalling

DB2 Load failed with “Unable to start a child process or thread”

It turns out DB2 db2sysc process was having too low max semid:

bash-3.00# prctl 5517
process: 5517: db2sysc

..

project.max-sem-ids
privileged      128       -   deny                                 -
system          16.8M     max   deny                                 -

..

 

Changed it to 4000 and it is working fine:

prctl -n project.max-sem-ids -r -v 4000 5517

 

vmware snapshot grow too large

This is vmware esx3.5. Today I found out the same mistake was made, with vmware snapshot not deleted for a very long time. Tried to delete the snapshot, but it timed out and after rebooting guest, I hit the same error as this one: http://sysadminhell.blogspot.com/2008/03/couple-of-vmware-issues.html. I followed the trick and killed vm, then started it up again. Got a snapshot named “Console Helper-1″. I tried to delete it again, it timed out again. It seems there is no way to see its progressing rate, the only way from vmware is:

This is vmware esx3.5. Today I found out the same mistake was made, with vmware snapshot not deleted for a very long time. Tried to delete the snapshot, but it timed out and after rebooting guest, I hit the same error as this one: http://sysadminhell.blogspot.com/2008/03/couple-of-vmware-issues.html. I followed the trick and killed vm, then started it up again. Got a snapshot named “Console Helper-1″. I tried to delete it again, it timed out again. It seems there is no way to see its progressing rate, the only way from vmware is:

watch -d “ls -touh –full-time *.vmdk” to just tell file modification timestamp changes for delta files.

(http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1007566)

But it seems it is in the process of deleting snapshot still.

 

puppet: StoreConfigs not supported without ActiveRecord 2.1 or higher

Kept getting this error after enabling storeconfigs for puppetmaster:

StoreConfigs not supported without ActiveRecord 2.1 or higher

Turns out it could only work with ActiveRecord major version 2. Need to downgrade activerecord on this Ubuntu 10.04:

gem list:

activerecord (3.0.1)

gem install activerecord –version 2.3.5

gem list:

activerecord (3.0.1, 2.3.5)

# gem uninstall activerecord –version 3.0.1
Successfully uninstalled activerecord-3.0.1

activerecord (2.3.5)

# /etc/init.d/puppetmaster restart
* Restarting puppet configuration management tool master server         [ OK ]

Reset “root” user password with Dell iDRAC

# racadm config -g cfgUserAdmin -o cfgUserAdminPassword -i 2 “calvin”
Object value modified successfully

Verify ok:

# racadm -r idrac_ip_address -u root -p calvin getconfig -g cfgUserAdmin -i1
Security Alert: Certificate is invalid – self signed certificate
Continuing execution. Use -S option for racadm to stop execution on certificate-related errors.
# cfgUserAdminIndex=1
cfgUserAdminUserName=
# cfgUserAdminPassword=******** (Write-Only)
cfgUserAdminEnable=0
cfgUserAdminPrivilege=0×00000000
cfgUserAdminIpmiLanPrivilege=4
cfgUserAdminIpmiSerialPrivilege=15
cfgUserAdminSolEnable=0

pca and zfs

perfect combination for OS patching, just tried this on Solaris 10U9: http://probably.co.uk/patching-a-live-solaris-10-system-with-lu-zfs-and-pca.html, worked great!

FusionIO card speed difference

/dev/md0 (RAID1 FusionIO, 320GB drive)

/dev/sda3 (Dell R910 local SAS drive)

Read performance:

# dd iflag=direct if=/dev/md0 of=/dev/null bs=1M count=10000

10000+0 records in

10000+0 records out

10485760000 bytes (10 GB) copied, 16.389 seconds, 640 MB/s

# dd iflag=direct if=/dev/sda3 of=/dev/null bs=1M count=10000

10000+0 records in

10000+0 records out

10485760000 bytes (10 GB) copied, 76.8867 seconds, 136 MB/s

# echo “scale=3;640/136″|bc -l

4.705

Write performance:

# dd if=/dev/zero of=/FusionMount/wuhai.txt bs=1M count=1000 conv=fdatasync
1000+0 records in
1000+0 records out
1048576000 bytes (1.0 GB) copied, 3.35998 seconds, 312 MB/s

# dd if=/dev/zero of=/tmp/wuhai.txt bs=1M count=1000 conv=fdatasync
1000+0 records in
1000+0 records out
1048576000 bytes (1.0 GB) copied, 9.21373 seconds, 114 MB/s

$ echo “scale=3;312/114″|bc -l
2.736

FusionIO cards in RAID0:

# dd iflag=direct if=/dev/md0 of=/dev/null bs=1M count=10000

10000+0 records in

10000+0 records out

10485760000 bytes (10 GB) copied, 10.1195 seconds, 1.0 GB/s

# dd if=/dev/zero of=/FusionIO/wuhai.txt bs=1M count=1000 conv=fdatasync

1000+0 records in

1000+0 records out

1048576000 bytes (1.0 GB) copied, 2.35316 seconds, 446 MB/s

Fusion IO cards RAID1

By default in RHEL5.5:

/proc/sys/dev/raid/speed_limit_min is 1000, and /proc/sys/dev/raid/speed_limit_max is 200000.

After changing /proc/sys/dev/raid/speed_limit_max to 800000, noticed RAID1 mirror resync speed goes up to 516M/sec, much faster than the default one, which is around 200M/sec.

Create puppet custom fact

1. Ensure (Better use puppet to ensure):

# cat /etc/profile.d/facter.sh
export FACTERLIB=/var/lib/puppet/lib

2. on puppet master server:

$ cat /etc/puppet/modules/gateway/lib/facter/gateway.rb
# gateway.rb

Facter.add(“gateway”) do
setcode do
%x{ip route | grep default | awk ‘{print $3}’}
end
end

3. Ensure puppet client has:

[main]

factpath=$vardir/lib/facter
pluginsync=true

in /etc/puppet/puppet.conf

Then facter | grep gateway would provide gateway IP as a fact.