Category Archives: Server Admin
Recently I installed Jailkit on Ubuntu 12.04 and then tried to use the vim editor to edit files as the jailed user (specifically a user jailed with the bash shell) and vim was behaving oddly. The colors on the terminal were just a gray (default color) and a bold white. After a little digging I found out this is how vim does syntax highlighting when it thinks that only two colors are available. Also, I was having trouble with the arrow keys not working – I could move around with HJKL but there also seemed to be lag and vim was hanging or would hang sometimes and was not responsive. I typed in set terminal and it told me ansi which is the default, “dumb” terminal. You can change vim to another terminal type, like xterm a few ways. Inside vim type :set term=xterm and that should do it Edit your .vimrc file (in your home directory) and add set term=xterm Before launching vim type export TERM=xterm to set an environmental variable Add that last command (export TERM=xterm) into one of your startup files like ‘~/.profileor ‘~/.bashrc This fixed the issue with the arrow keys, the lag and hanging, but I still only had two colors. After many hours of digging I realized that with Jailkit on Ubuntu even if you do jk_init -v /home/jail editors to install joe and vim and emacs you still get this problem. I did a stack trace on vim and even turned on debugging … Continue reading
The stat command on Ubuntu and OS X behave differently and I’d like to have the functionality of the GNU / Ubuntu version of stat available on OS X – if there is such a thing. I have already used homebrew to install gnu-sed and I see similarly that a lot of the GNU utilities are available from: brew install coreutils findutils gnu-tar gnu-sed gawk gnutls gnu-indent gnu-getopt I know stat on OS X might be very specialized because of the OS X file systems that may be present, but I’d ALSO like to have the linuxy version if it is available. As it turns out, it is. The GNU version of stat can be accessed on OS X by installing a package / keg called coreutils which includes the following utilities: base64 env mknod runcon touch basename expand mktemp seq tr cat expr mv sha1sum true chcon factor nice sha224sum truncate chgrp false nl sha256sum tsort chmod fmt nohup sha384sum tty chown fold nproc sha512sum uname chroot groups numfmt shred unexpand cksum head od shuf uniq comm hostid paste sleep unlink cp id pathchk sort uptime csplit install pinky split users cut join pr stat vdir date kill printenv stty wc dd link printf sum who df ln ptx sync whoami dir logname pwd tac yes dircolors ls readlink tail dirname md5sum realpath tee du mkdir rm test echo mkfifo rmdir timeout These GNU utilities are available on Mac OS X but the one caveat is that they are … Continue reading
The Rackspace documentation says on exiting rescue server mode: Once you are done troubleshooting your system, you can exit Rescue Mode by clicking the link labeled Exit Rescue Mode in the Rackspace Cloud Control Panel under your Server Details page. I couldn’t seem to find the link. The solution? Visit the list of servers. Click the server name to go to the details page. And the most important key? Wait. It may take a few seconds (~10) before the “Exist Rescue Mode” box pops up with an option to quit recovery mode and reboot into normal server operations.
I’m now starting to use Rackspace after a having a lot of experience with Amazon AWS and so I’m having a hard time understanding a few things about the way Rackspace works. One of these things is “Disaster Recovery” for a Rackspace “Cloud Server’s” primary drive primary drive. There is a lot of server terminology with Rackspace so for clarification I’m talking about the ones in the Cloud Servers control panel that are in this tab: So my point of confusion is this: If I screw up something big on AWS, like the /etc/fstab file and the server won’t boot, I can use the AWS control panel to get the console log: If I need to edit things on the primary drive I can “detatch” it from the instance and attach it to another server, and then access the files on it. I searched the Rackspace knowledge base and also read the Disaster Recovery blog post which mentions three ways of doing disaster recovery with Rackspace: Take regular snapshots and restore the instance from one of those Do manual file system and database backups to have a copy of your data NOT on the primary drive Replication with Manual Failover (seems like overkill) I also saw that it is possible to boot the server into “recovery mode” but I haven’t tried it yet. The way I’m planning on running my rackspace server is attaching another drive (aka Storage Volume) and putting all the application data on that. I am also … Continue reading
The hash utility shall affect the way the current shell environment remembers the locations of utilities found as described in Command Search and Execution. Depending on the arguments specified, it shall add utility locations to its list of remembered locations or it shall purge the contents of the list. When no arguments are specified, it shall report on the contents of the list. The following option shall be supported: -r: Forget all previously remembered utility locations.
Recently I was checking out the Better WP Security plugin for WordPress and noticed that the plugin comes with a cool blacklist of useragents from HackRepair.com (btw that website seems to have a lot of great info on fixing hacked wordpress sites). Anyhow I found that after installing the plugin my .htaccess file was updated and included a new section to block malicious IPs and user agents. The list looks like this:
Amazon EC2, CloudFront, and all of the other Amazon Web Services have received a CSS / Design refresh after a few years of using the previous design. A few highlights on the new design: Dropdown Selection of all AWS Services This has been available for at least a few months. Amazon was adding so many “tabs” to the previous horizontal layout that they ran out of space. Configurable View Options Much like WordPress’s “Screen Options” Amazon has added some settings for how you view items in the toolbar: Collapsable Sidebar Amazon now gives you the option to collapse the sidebar more easily (previously you could resize it). Toggling it is a more effective way to quickly see more of the columns in the panel on the right. Quick Toggle for the Properties Panel There are now three icons in to quickly toggle sizes in the Properties Panel at the bottom There have been a few other changes to try and make the panel more “responsive” and friendlier for small screen sizes. However, I would still rather use a mobile app to manage EC2 instances on my phone.
Hello again from AWS re: Invent! The second day of AWS re: Invent in Las Vegas started off with a great talk from Amazon.com CTO Dr. Werner Vogels. After a brief recap of yesterday’s announcements (Amazon Redshift and the S3 price reduction), Werner discussed the role of system architecture in today’s world of unconstrained, programmatic access to processing, storage, and network resources. He emphasized that new architectures must be scalable, fault-tolerant, high-performance, and cost-effective. His talk included guest speakers from Pinterest and Animoto, along with live, dynamic demos conducted by AWS Evangelists Matt Wood and Simone Brunozzi. Werner announced a pair of new Amazon EC2 instance types, one for high storage applications and another for high memory applications. He also announced the AWS Data Pipeline. New Amazon EC2 instances Two new Amazon EC2 instance types will be made available to customers in the US East (Virginia) region in the coming weeks. High Storage Instances are a new Amazon EC2 instance optimized for customers that need high storage depth and high sequential I/O for applications like data warehousing, Hadoop and data-intensive HPC. High Storage instances will be available in a single size, High Storage Eight Extra Large (hs1.8xlarge), and have 16 virtual cores, 24 hard disk drives, 48 TB of storage capacity, 117 GiB of RAM and 10 Gigabit Ethernet networking. Cluster High Memory instances are another new Amazon EC2 cluster instance type optimized for memory-intensive analytics and scientific computing. Cluster High Memory instances will be available in a single size, … Continue reading
Greetings from Las Vegas, host city for AWS re: Invent! AWS Senior Vice President Andy Jassy kicked off AWS re: Invent with a rousing 90 minute keynote presentation in front of 6,000 attendees, with another 13,000 watching the live stream. Andy’s talk covered a lot of ground! Starting with the history and growth of AWS over the last 6.5 years, he talked about important AWS use cases including web site hosting, gaming, social media, high performance computing (HPC), media distribution and streaming, disaster recovery, and more. He noted that AWS has hundreds of thousands of customers in 190 countries. This includes over 300 government agencies and 1500 educational institutions. Andy also used this opportunity to reveal some updated statistics on the growth of AWS – over 1.3 trillion objects in Amazon S3 (accessed at a rate of over 835,000 requests per second) and 3.7 million Hadoop clusters launched on Elastic MapReduce in the past two years. During the keynote we also announced Amazon Redshift, our new data warehouse product and an Amazon S3 price reduction, drawing applause from the live audience and a similarly appreciative reaction online. Amazon Redshift Amazon Redshift is a fast and powerful, fully managed, petabyte-scale data warehouse service in the cloud. Redshift offers you fast query performance when analyzing virtually any size data set using the same SQL-based tools and business intelligence applications you use today. With a few clicks in the AWS Management Console, you can launch a Redshift cluster, starting with a few hundred … Continue reading
Dear EC2 User, I work in the Business Development team for Amazon Database Services. We co-ordinate interactions between AWS customers and the product teams for DynamoDB, ElastiCache, and Amazon Relational Database Service (RDS). In case you’re not familiar with RDS, it’s a web service designed to make it easy to set up, operate, and scale a relational database in the cloud. We’re running a series of free webinars that will highlight examples and best practices used by RDS customers to help improve performance, reduce costs, and eliminate most of the effort of database administration. Details of the next event are: Save time and effort. Focus on your app with Amazon RDS Amazon RDS simplifies database administration, giving you more time to build and optimize your applications 13 September 2012, 10.00AM to 11:00AM PDT This webinar will provide detailed information on customer use cases and best practices.Topics include: performance, security, migration and data protection. I hope you can make it. Regards, David Pearson Business Development Manager