Casey needed me to install APC cache for the Scriblio project. It’s a PECL module, and pecl install apc gives an error. Here are some great instructions for getting it all to work.

We backup our Oracle databases using RMAN and then write the backup pieces out to an NFS share. This has always worked well, but RMAN started complaining that the NFS share was not mounted with the correct options when we upgraded to Oracle 10G. After some poking around in the docs I finally came up with a set of mount options that work.

Vfstab entry on a Solaria 8 box:
nfsserver.domain.com:/path/to/remote/mountpoint /local-mountpoint nfs 0 yes rw,bg,intr,hard,timeo=600,wsize=32768,rsize=32768
Manual mount on a Solaris 8 box:
mount -o rw,bg,intr,hard,timeo=600,wsize=32768,rsize=32768 nfsserver.domain.com:/path/to/remote/mountpoint /local-mountpoint

According to the docs, the options on a Linux box are pretty much the same, except you would add the following:
nfsver=3,tcp

Creating a properly offset slab of disk for Linux systems on your CLARiiON is not just a matter of creating a partition using the default fdisk values. The reason for this is that disk management utilities for Intel based systems generally write 63 sectors of metadata directly at the beginning of the LUN. The addressable space begins immediately after these initial sectors causing the CLARiiON to cross disks, especially when writing larger IO because it doesn’t match up with the stripe element size (usually 64k).

To get around this, you have to align the partition in such a way that it will start writing data on a sector that will mesh up nicely with the stripe element size. In this case, 128. Below is an example of how I create partitions on our CLARiiON for Linux systems. Check out the EMC Best Practices for Fibre Chanel storage white paper for more detail.

/sbin/fdisk /dev/emcpowera
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.

The number of cylinders for this disk is set to 39162.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)

Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-39162, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-39162, default 39162):
Using default value 39162

Command (m for help): x

Expert command (m for help): b
Partition number (1-4): 1
New beginning of data (63-629137529, default 63): 128

Expert command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

If you’re running Solaris 8 or 9 and an upgrade results in broken SSH X11 forwarding, the problem may be Sun’s socfs bug. The symptom will be SSH’s failure to set the $DISPLAY variable and an error in your system log looking something like this:

Jun 3 09:40:24 servername sshd[26432]: [ID 800057 auth.error] error: Failed to allocate internet-domain X11 display socket.

To fix this, you can either install Sun’s latest socfs patch for your version of the OS, or simply force sshd into IPv4 mode by doing the following:

Edit you sshd_config file, adding the following:

# IPv4 only
ListenAddress 0.0.0.0


Edit your sshd startup script to issue a “-4″ to sshd on start:

case “$1″ in
’start’)
echo ’starting ssh daemon’
/usr/local/sbin/sshd -4
;;


Restart sshd, and that should pretty much do it… Enjoy.

All next week I’ll be taking a cave diving class on my CCR down in North Florida. Cave diving has been a dream of mine since reading an article about Sheck Exley’s exploration of the Nacimiento Mante cave system in Mexico. At a time in my life when I almost bought into the idea that divers should not venture deeper than 130 feet, there I was, reading about a man who had plunged to a world record depth of 881 feet and returned safely to the surface after 14 hours of decompression. It was as if the wool that had been pulled over my eyes by the recreational diving agencies had suddenly been removed, and I was left totally inspired. I remain inspired to this day, and I am honored to have the opportunity to learn cave diving from legendary cave and technical diver Tom Mount.

We just noticed that the time was very far off on our sparkly new VMware EXS 3.5 server. When I went to run ntpdate to bring it up to sync, I was suprised to find that it could not make a connection to the time server because outbound UDP 123 traffic was blocked by the [...]

Below is a list of RHEL system configuration changes that Oracle 10G requires before it is installed.
First, check the following kernel parameters using the commands below:

/sbin/sysctl -a | grep kernel.shmall
/sbin/sysctl -a | grep kernel.shmmax
/sbin/sysctl -a | grep kernel.shmmni
/sbin/sysctl -a | grep kernel.sem
/sbin/sysctl -a | grep fs.file-max
/sbin/sysctl -a | grep net.ipv4.ip_local_port_range
/sbin/sysctl -a | grep net.core.rmem_default
/sbin/sysctl [...]

Earlier today I had a problem with some Macs that could not establish SMB connections to our Windows File Server. There was no quick error, so the problem really “felt” like a firewall issue but strangely I was able to make a CLI connection to the file server using smbclient:
smbclient //server/share -U domain/username
Password:*******
Domain=[DOMAIN] OS=[Windows Server [...]

It turns out that the sleeping little girl in Hillary Clinton’s “Red Phone” TV advertisement is supporting Barack Obama. The Clinton campaign used stock footage of the girl who is now of voting age and calls “Red Phone” ad “Fear Mongering”. I guess the Clinton crew should have thought about that.

Lots of small companies want to hire an IT department in a can… You know, the ones who hire only one person to run their Linux servers, code their websites, architect their networks, support their users and order more printer toner. It’s a hard job, but it’s pretty common to see them advertised. What I [...]