The case of the missing SSH keys
I built a couple of new Solaris 10 hosts today using a stripped down image, and was greeted with the following error when I tried to log in: The server was spitting out "no kex alg" errors, which appear to be due to key exchange issues. I poked around my sshd_config file, and for some reason the host host keys weren't generated when the ssh service initialized. To fix this, I ran the ssh service with the -c option (this generated the RSA and DSA host keys): added the host keys to my sshd configuration file: And then ran 'svcadm refresh ssh' to restart the service. Once that completed, I was able to login to the host…
$ read more →Getting e-mail updates when new CentOS packages are available
A while back I wrote about yumnotifier, and how I was using it to get notified when new packages were available for my CentOS installations. Dan posted a comment asking me why I wasn't using the yum-updatesd e-mail notification support. I recently (CentOS 5.2) started using the yum updates daemon to get notifications, but didn't update the previous post with this information. Configuring the daemon to generate e-mail notifications when new updates are available is as easy as adding the email_to and email_from settings to the /etc/yum/yum-updatesd.conf configuration file: email_to = matty@prefetch.net email_from = root@server1.prefetch.net Since I use kickstart to build my hosts, I have a postinstall action that adds these items to the configuration file and adjusts the email_from with the name of the server…
$ read more →Speeding up md device rebuilds
I manage a large RAID5 array at home, and had one of my disks crap out over the weekend. Once I physically replaced the drive and told mdadm to reconstruct the array, I noticed that the rebuild was going to take days to complete. After a bit of digging, it appears that the mdrecovery process throttles itself to prevent the recovery process from consuming all I/O. I was most concerned about getting the RAID array back into a consistent state, so I decided to play around with the speed_limit_max setting to speed up the recovery…
$ read more →Finding hardware details on Solaris 10 hosts with SMBIOS
I have previously written about the Solaris smbios utility, and how the utility can be used to discover various items about the hardware platform you are running on. While reviewing one of my mailing lists over the weekend, I came across a post that describes the SMB_TYPE_BASEBOARD and SMB_TYPE_SYSTEM properties. In most cases these two properties will allow you to discover the hardware platform you are running on, and details about the motherboard in use: If you are building an inventory system, or just want to see what type of system is in use, this information will be of great value!
$ read more →Viewing and changing network device properties on Solaris hosts
Project brussels from the OpenSolaris project revamped how link properties are managed, and their push to get rid of ndd and device-specific properties is now well underway! Link properties are actually pretty cool, and they can be displayed with the dladm utilities "show-linkprop" option: As you can see in the above output, the typical speed, duplex, mtu and flowctrl properties are listed. In addition to those, the "maxbw" and "cpus" properties that were introduced with the recent crossbow putback are visible. The "maxbw" property is especially useful, since it allows you to limit how much bandwidth is available to an interface…
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