Rick Mitchell Solutions - RMSBlog

Dell Equallogic PS6500 SAN's - impressions

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Fri, 05 Feb 2010 18:02:00 +0000

I have had the pleasure of working with two Dell Equallogic PS6500 SAN's over the past month or so and I thought it would be a good idea to put my ideas out there.

I am going to start with my complaints with the product because overall I am very happy with our purchase. However, with any product there is always room for improvement.

My biggest gripe is the performance monitoring aspect of the SAN itself. This is obviously a big deal to data administrators and probably more so in the iSCSI world where bandwidth is everything. The performance monitoring is basically watered down to the point of being too simplistic. I would like to see more raw data and less Java induced graphs. I realize that the target market for these SAN's are businesses who do not have SAN experience on staff but there should be some better tools to go deeper into looking at performance.

I have spoken about the firmware update process in the past, but I still feel this needs attention. I am not sure why the SAN itself cannot go out and grab the new firmware - then alert the administrator that new firmware is available if you want to update. It feels cumbersome to go through the manual steps of getting the firmware updated for the box.

The Auto Snapshot Manager software which is part of Dell's Host Integration Toolkit is a nice idea but the software feels a bit flaky to me. There are two editions that I have used - one is for Windows Applications and one is for VMWare. The Windows edition will make "application aware" snapshots of SQL Server/Exchange databases so you could actually restore from that snapshot without the worry of data corruption. The software works as expected but after a reboot sometimes the manager will not know how to find the vss-control volume (the volume that the software uses to induce the volume shadow copy aware snapshot) so you have to go back into the iSCSI initiator and and connect to the volume before it will work. The VMWare piece is for some reason a web-based piece of software that looks like an afterthought in appearance but does actually work. I don't like the ability to not be able to send email alerts for failed snapshots with the VMWare package but I hope that is something that will be fixed soon.

I have not tried the replication piece yet as I am waiting for the 100 megabit point to point Cogent circuit to be installed to my second data center but I am anxious to see how it works in the real world.

Overall, I am very happy with the SAN's and still recommend them but there is some room for some minor improvement along the way.

VMware KB: USB devices not supported in ESX host virtual machines

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Fri, 05 Feb 2010 17:50:00 +0000

VMware KB: USB devices not supported in ESX host virtual machines

I am going through a virtual server migration at one of my data centers. The idea of moving away from older, non-standard hardware and going to a virtual platform is exciting for any IT nerd but there are some pitfalls along the way that you must keep into account. One of these pitfalls is around USB devices that your servers may use today. One of the applications that we use has an old USB Key that is used for license verification. Unfortunately, ESX/ESXi does not support adding USB devices to individual virtual machines. Apparently this support is in the works but you have to buy a USB over IP device in order to make it work properly. Who knew?

It goes to show that when you plan on doing a large scale conversion, you need to think about everything that the server does and to make sure it is supported on a virtual platform before you dig in. Support is probably a bad word since there are still many vendors out there that will not officially support their software on a virtual machine (Hello Landmark!). Of course their software will run just fine on a VM but when you call them, do not under any circumstances tell them it is running under a VM or they will stop talking to you immediately.

VMware ESX/ESXi 4.0 not working with Intel Dual/Quad PCIe NICS

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Mon, 25 Jan 2010 21:10:00 +0000

VMware ESX/ESXi 4.0 Driver CD for Intel 82575 and 82576 Gigabit Ethernet Controller

Even after installing update 1 for ESX/ESXi 4.0, the OS still will not see these NIC's as being available to your system. Apparently after talking to VMWare support, there is an updated IGB driver available that you can download although it is a bit hidden on VMWare's website.

You will want to SCP this over to your server and then follow the instructions for an offline installation. The only problem is that you will have to take your ESX server into maintenance mode to do the update. Once it is done and you reboot, you can then see the NIC's and use them as part of your VM configuration.

Configure port forwarding on Juniper routers and ScreenOS

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Tue, 19 Jan 2010 13:58:00 +0000

Juniper Networks - ScreenOS Cookbook Recipe 8.7 - Configure Destination PAT (Port Address Translation) - Knowledge Base

There is no easy way to say this but if you are used to dealing with Cisco devices over the years and are suddenly thrust in front of a Juniper device - you will think that Juniper is very weird. I am sure there are folks who absolutely love Juniper but for me I personally don't like dealing with them. In any event, if a client has a Juniper device and you need to configure it, you dive right in and make the best of it.

One of the things that I find odd is the way that port forwarding works on the device. Once you see it you will think it makes perfect sense but unfortunately the documentation on the subject is lacking.

For example, lets assume your firewall has an external interface on 1.1.1.1 and you have 4 usable IP addresses. You want to host an internal WWW server on 192.168.1.10 that is connected to the internal LAN. Here is the syntax to make this work:

set arp NAT-DST
set address untrust server-www-public 1.1.1.1/32
set policy from untrust to untrust any server-www-public http nat dst ip 192.168.1.10 port 80 permit

The weird part for me was the untrust to untrust which didn't make a whole lot of sense. In any event, that will work.

Now, what if you wanted to host something via NAT that came through the external IP of the firewall interface?

In this case, we need to change the admin port of the firewall to something different if we want to host WWW traffic and then do the NAT'ing:

set admin port 8080
set service "HTTP-8080" protocol tcp src-port 1024-65535 dst-port 8080-8080
set interface ethernet0/0 vip untrust-ip 80 "HTTP-8080" 192.168.1.10
set policy id 1 from untrust to trust any vip(ethernet0/0) HTTP permit

A bit odd but gets the job done. Good luck.

Configuring Volume Shadow Copy on Windows Server 2008 - Techotopia

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Tue, 19 Jan 2010 13:36:00 +0000

Configuring Volume Shadow Copy on Windows Server 2008 - Techotopia

Just a quick heads up for anyone configuring shadow copies on Windows Server 2008 - you no longer can right click on the volume under My Computer to enable shadow copies. You have to go into disk management and enable on each volume there first. I am not sure why they made this change but if you start scratching your head and wondering where it went - this is how you will find it.

DisableMSI and Windows Server 2008 R2

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Mon, 18 Jan 2010 22:02:00 +0000

DisableMSI (Windows)

When I install Server 2008 R2 I have came across a weird problem that will prevent me from running any MSI installation program even though I am an administrator on the box.

The system administrator has set policies to prevent this installation

Of course, I haven't set any policies to prevent this but I found the following registry key which will override this setting. Apparently by default the policy with R2 is to disable all installs of MSI's - fairly draconian but better than the default I guess:

HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Installer

REG_DWORD

DisableMSI set to 0

Windows Server 2008 R2 - adprep

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Mon, 18 Jan 2010 21:56:00 +0000

Adprep

Windows Server 2008 R2 has added some additional Active Directory objects that need to be imported into your domain and forests before it can become a domain controller. The tool that you will need to use to get your forest/domain ready for this new OS is called "adprep" and it can be found in your Windows Server 2008 R2 CD. Unlike previous versions of adprep, R2 includes a 32-bit (adprep32.exe) and a 64-bit (adprep.exe) copy for you to use. You have to run this tool on an existing domain controller so know your architecture before you start copying around the folder to your servers. You will need to do the following:

adprep /forestprep

adprep /domainprep

adprep /rodcprep

The first command will add the necessary objects into your forest, then add the necessary objects into your domain and finally it will prep your domain for the new concept that is read-only domain controllers. Once you have ran these commands and AD has replicated throughout your network, you can safely run dcpromo.exe from your Windows 2008 R2 server and make it a domain controller.

PS6500E installation and configuration

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Tue, 12 Jan 2010 19:55:00 +0000

One of the nice things about setting up a Dell Equallogic SAN is how amazingly simple it is to configure. You would think that for an expensive piece of equipment that it would be harder to configure and get going, but fortunately that is not the case.

After unpacking all 48 hard drives and inserting them into the chassis which definitely took quite a bit of time, plugging in three power cables and inserting an ethernet cable - it took right off. I was pretty impressed with the fact that none of the drives that shipped with the unit was bad - you would usually expect at least one to be bad out of 48 but not in this case. I inserted the Dell Configuration assistant CD into one of my servers and was able to run the remote configuration assistant where I got to set up the networking information and set the initial passwords and group membership. Since this was my first SAN, I set it up in its own group and assigned it a static IP address. I created a single storage pool of RAID5 in order to begin my testing and then the unit was up and functional.

I was able to log in to the web interface to the unit and do some more configuration and take a look at all of the settings. One thing I noticed was that the firmware was out of date on the unit but you cannot download directly from the SAN - you must first set up an Equallogic support account and then download the firmware separately. This was a bit of a pain and hopefully something that can be a bit more automated in the future.

Right now I have two volumes configured with IP address access going to a VMWare ESX server and a Windows 2003 Server for testing purposes. The Microsoft iSCSI initiator installation is very straight forward and setting up my targets were very simple.

I enabled SNMP monitoring through Solarwinds Orion and so far everything looks good.

Modifying the All Users profile in Vista or Windows Server 2008

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Tue, 12 Jan 2010 14:51:00 +0000

The Virtual World of Peter Fitzsimon : Modifying the All Users profile in Vista or Windows Server 2008

Another strange thing about Windows Server 2008 is the new location of the all users profile:

C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup

This is another oddity and I am not really sure why it was changed but in any event if you run BGInfo like I do, you will want to place your shortcut here for it to run on every user login.

Installing VMware vCenter on Windows Server 2008 R2

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Tue, 12 Jan 2010 14:48:00 +0000

Installing VMware vCenter prerequisites on Windows Server 2008 R2 | Servers and Storage | TechRepublic.com

Windows Server 2008 R2 is now officially supported as a VMWare VCenter server since 4.0 update 1 has been released. However, you may run into some difficulty getting it installed as things are a bit different in the Windows 2008 world.

One of the most common mistakes is how to add a 32bit DSN to your system since Windows 2008 is 64-bit. If you launch the ODBC Administrator from the start menu, this gives you the 64bit drivers which is not supported with VCenter at this time. You need to launch the DSN configuration from the command line in order to get the 32bit drivers:

c:\windows\syswow64\odbcad32.exe

This will allow you to create a 32bit DSN assuming you have installed the 32bit SQL Server client drivers on your box.

Once this is set up, the rest is pretty easy and will work without trouble.

VMware Site Recovery Manager Service installation logs

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Tue, 12 Jan 2010 14:42:00 +0000

VMware Site Recovery Manager Service Account « Jeremy Waldrop's Blog

Today I ran into a problem installing Site Recovery Manager 4.0 update 1 where it would attempt to start the service and fail. The error message told me to check the server logs but I could not find any documentation on where these would be. Luckily I ran across this blog entry which details the location of the installation logs:

C:\Documents and Settings\All Users\Application Data\VMware\VMware Site Recovery Manager\Logs

I have no idea why VMWare would choose to put these logs in this odd location but once you are there you can quickly determine why the service is not starting. My problem was with SQL Server authentication which I was quickly able to correct and get the service to start properly.

The SAN's have arrived

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Fri, 08 Jan 2010 20:09:00 +0000

Today, 520 pounds of PS6500E storage arrived through the delivery company. My only complaint I have is that the drives arrived in a box and you have to load the array yourself. No big deal but you would think for $80k a piece that they could at least load the array. In any event, I am super-excited to get these built and rolling.

VMWare servers have arrived

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Wed, 06 Jan 2010 19:12:00 +0000

Part of the joy I get from my career is the ability to play with new hardware. Yesterday I got to install VMWare ESX 4.0 on three brand new Dell R710 servers that were loaded with dual 2.93ghz quad core processors and 96gb of RAM with (12) gigabit NIC's in each box. This is all part of large in-house Disaster Recovery project where we will have two data centers that are separated by 2000 miles or so with a 100megabit point to point fiber connection. Two Dell PS6500E SAN's with 48tb raw capacity will be on each side and replicate the data to each other respectively. We will utilize VMWare VMotion to keep the hardware completely transparent and Site Recovery Manager to automatically bring up each data center to the respective hardware in the case of a complete failure. We are going to be able to reduce our physical server count down to 8 total servers for the entire enterprise which is pretty amazing and house our internal DR facilities. I am very excited about this project even though it is in the early stages but I must admit I am impressed so far with VCenter Server and Site Recovery Manager 4.0 - even the licensing aspect of everything has been a breeze to set up and configure. As I travel down this path I will be blogging more and more about this project as I find this topic extremely interesting. Stay tuned!

Adobe Reader automatic updater coming soon

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Wed, 06 Jan 2010 18:55:00 +0000

Happy New Year to everyone! It is that time of the year to talk about some of the things that really bother me - a virtual cleansing if you will. One of the things that I truly hate to live with is Adobe Reader and Adobe Acrobat. Lately these tools have become a thorn in my side due to the countless number of security vulnerabilities that have been discovered and the need to "update" to newer versions each time a problem is found. I use the term "update" loosely because Adobe never really patches their software, they just release complete, brand new installs for a new version. Going from version 9.1 to 9.2 requires a complete 40 meg roll out of a new piece of software and not a simple patch. This causes problems with settings that were once installed as well as file associations with other PDF software such as full blown Acrobat. Who knew that pushing out new Adobe products would be such a pain??

Today comes word that Adobe has finally realized just how insane their approach to patch management has become and is working on a beta for a new Adobe updater package to be shipped with software later this year. I don't understand what has taken them this long but I for one cannot wait for this to get here.

http://www.macworld.com/article/145475/2010/01/reader_acrobat.html?lsrc=rss_main

Upcoming Certification tests

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Fri, 18 Dec 2009 20:42:00 +0000

It is that time of year again and I have decided to take a couple of certification tests to enhance my marketability and skills. Solarwinds now has the Solarwinds Certified Professional certification and I have used/recommended their products for years now. Their network management and alerting software Orion is the best in the business and I am glad to see that they have begun to offer this certification. While the test is not geared directly towards Orion and the concepts can be used with any network management software, there is a section geared directly towards Orion. I have looked through the study guide and it appears to be fairly straight forward for someone who has used the product plus I got the added bonus of receiving a free exam voucher for being one of the first 500 people to sign up for the test. This deal is running until the end of December or when 500 people register so definitely sign up if you are thinking about taking the exam.

The second certification I will be going for should be cake - it is Apple's new Snow Leopard test for the Apple Certified Support Technician. I have not taken an Apple test before but after two years of heavy use and support of other Mac's I feel that now is the time. Apple encourages you to take the test by advertising your certification on their site and allowing people to find certified support personnel in their area. This is a great idea and one that I would like to take advantage of in order to gain additional clients.

I will keep everyone up to date as to my progress and I hope to have some updates in the upcoming weeks.

Using ESEUTIL to diagnose/repair an Exchange 2007 database

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Fri, 18 Dec 2009 17:30:00 +0000

Eseutil: Exchange 2007 Help

Anyone who has dealt with Exchange knows that ESEUTIL is the tool you can use to do any type of repair or integrity check on your database. With Exchange 2007 this utility has been expanded to include repairing the new queue database for your Hub or Edge Transport servers as well.

Using ESEUTIL still requires that the database be offline so that you can do any type of activity to the database such as defragging to gain the free space back from an EDB file. Normal online maintenance can run while the database is up and functional but you cannot use those tools manually on your own. Normal defragmentation can take up to two weeks to occur in an online state so if you need the additional space immediately you will have to take the database offline in order to use ESEUTIL.

The major difference in the past is now the queues are in a database format and are no longer individual flat files that are kept in various folders on your server. This can be a good or bad thing depending on how you look at it. It is more difficult to get an idea if your queue is hosed or what the offending message may be so you will need to use the queue viewer in your toolbox of the Exchange Management Console or a PowerShell cmdlet in order to figure out what is going on. This database as I have recently learned can get corrupted so it is important to know that you may have to use ESEUTIL against this database as well - it is called mail.que by default on your box.

MxToolbox - test your external email servers

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Fri, 18 Dec 2009 17:01:00 +0000

Email Server Test - Online SMTP diagnostics tool - MxToolbox

Do you want to know if you have properly configured your external mail server to not be an open relay for spambots? Do you want to see if your mail server is blacklisted on various spam sites? MxToolbox is a free site that allows you to test your mail server for a variety of issues and has a simple interface to take steps to fix any problems that might be found. There are many sites that want you to pay a fee for these tests but I have found MxToolbox to be great and highly accurate.

Yesterday I ran into a problem where an external mail server got blacklisted due to a spambot infection on a machine on our network that was NAT'ing through the same IP address of our mail server. I had the machine pulled off the network within a few minutes of seeing the problem but at that point the damage was already done to our reputation and we started getting NDR's from various servers due to our blacklisting. MxToolbox allowed me to see who had blacklisted us and start the removal process all from one spot. This saved a lot of time and effort on our part instead of having to guess which list was blocking us.

Another good tip from yesterday is to block SMTP traffic flowing from your network except from your Edge Transport server. This will stop any spambot from originating on your network and not cause these types of issues. I was able to see who the culprit was by looking at all active connections on our firewall to port 25 of an outside address. I now have a firewall rule set up to block these types of connections in the future.

Differences between Standard and Enterprise editions of Exchange 2007

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Wed, 16 Dec 2009 21:56:00 +0000

Microsoft Exchange Server: Exchange Server 2007 Editions

One of the questions people often ask when figuring out what version of Exchange that they actually need is the limit on the size of the database. Microsoft has done a good job of putting together a quick and simple explanation of the differences on the page above which is really helpful for folks trying to plan and manage their Exchange environment. The cost of an Enterprise license is fairly more expensive than a standard edition, but you lose the flexibility and redundancy in your organization. For example, you cannot use CCR for clustering your Exchange environment and you are limited to just 5 storage groups with 5 different databases. The theoretical limit on exchange database size is 16tb which is the same for each version of Exchange but in reality the limit is much lower.

Microsoft has a support document that states the recommended maximum size for a database is 100gb due to the I/O involved with transaction logging and backup/restore functionality. You of course can go much higher but be prepared for some headaches along the way such as log file replaying and recovery time being a lot longer. It is a good practice to try to keep the databases around 100gb if at all possible. This is another advantage of the enterprise edition in that you can manage 50 different databases on a single server instance.

Always remember to keep your logs separated from your database on different logical volumes so that the I/O can be properly spread between the two sets of data. Most of this is common sense and very logical, but if you take these steps up front you will save a lot of headache down the road.

Upgrading Exchange 2007 to Service Pack 2

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Wed, 16 Dec 2009 16:01:00 +0000

This past weekend I wanted to get our Exchange environment up to date and I decided to install SP2 as well as Rollup 1 on our three Exchange 2007 servers. This article will give you some hints to help you along the migration path that you may want to consider.

Install SP2 and Rollup 1 on your Edge Transport or Client Access Server FIRST. This will allow you to continue to proxy requests to your back-end servers since SP2 is backwards compatible with SP1. If you decide to install SP2 on one of your Mailbox servers first, and your OWA proxy is not up to date, then your users will no longer be able to access their mail via webmail - they will get an error about the version level being unsupported on the back end. Amazingly though ActiveSync will continue to function in this scenario.

You do not have to reboot in order to install SP2 or Rollup 1 but do allow for some maintenance for this to occur. In my environment the install took approximately 1 hour to complete per server.

Once you have installed SP2, any changes you made to the OWA access such as SSL requirements are replaced with the defaults. I found this the most frustrating since I took some time to get this all set up the way I wanted. I wish they would leave these settings alone when you install the update. As always, document your configuration with notes and/or screenshots so that you do not get in a bind and have to re-invent the wheel once you install the update.

Overall, the process went fairly smooth and was pretty straight forward. Keep in mind that any upgrade or changes you make to your email environment should be considered critical and that backups before and after the changes are crucial. Testing extensively should be done in order to make sure that the transition will be as seamless as possible.

Using MFCMAPI to find bad messages in Exchange 2007

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Wed, 16 Dec 2009 15:55:00 +0000

MFCMAPI

Yesterday I had a major Exchange 2007 outage on a server that I will speak more about later but I found a neat tool yesterday to give you some insight into what is going on with messages in your queue. Believe it or not, but sometimes a bad message or a bad meeting request can cause your Mail Submission or Transport Service to take a major headache and slow processing down to a crawl. In order to properly diagnose what is going on you can always use the Queue Manager to see messages that you can suspend processing, but unfortunately you cannot delete an individual message or request this way. Using MFCMAPI you can actually use a MAPI connection to Exchange and find and delete offending messages that you think may have been the problem. It is a handy tool to keep in your toolbox as you make your way through Exchange issues.

BackupExec 12.5 sp3 and Exchange 2007 GRT MAPI errors

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Tue, 15 Dec 2009 14:14:00 +0000

BackupExec 12.5 has a technology for Exchange that they call GRT which allows for the granular backup and recovery of Exchange 2007 so that you do not have to recover an entire database in order to bring back a certain mailbox or message that was lost. In theory, this works great but unfortunately theory and reality are two different things.

I did an upgrade of BackupExec 12.5 to SP3 and before the upgrade GRT appeared to be working fine. However, after closer inspection, it wasn't really working but was not throwing errors either. The problem was that GRT uses a MAPI connection to your backup once it is on tape or disk to create the catalog of all of the mailboxes and the messages that are contained inside of them. If the account does not have full Exchange 2007 permissions on the organization or server, then this catalog process will fail with a MAPI credentials error. My original problem was that GRT was only working for a few mailboxes that actually had permissions to be logged in to from my backup account but for the vast majority it was failing. However, BackupExec relayed that the job was a success even though most of my mailboxes were failing to be indexed properly. This is obviously not good.

Once I upgraded to SP3, the problem got worse. Now, I was getting a MAPI error once the database and logs had been backed up and no indexing was taking place. I checked all of my permissions, created a new AD account with the appropriate permissions to exchange, and yet it still failed. Finally, I stumbled across an article that mentioned hardware compression as a possible culprit of the MAPI error since it was trying to log in to the image on the tape - why it does this is beyond me. I turned off hardware compression for this particular job, re-ran it and magically all of my indexes were created properly using MAPI and GRT.

I believe this to be a major bug in that you really need to verify all of the mailboxes are being indexed properly and Symantec needs to fix BackupExec so that it doesn't read the MAPI information from the backup media. This should be done against the actual database on disk in my opinion. Hopefully this will be fixed in a future release but for now, this should save you a lot of time that I went through this past weekend to solve this issue.

MacUpdate Desktop 5.0

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Thu, 03 Dec 2009 14:50:00 +0000

MacUpdate: MacUpdate Desktop 5.0

One of the biggest problems with Windows is keeping all of your applications up to date and fully patched, even with enterprise patch management software such as BigFix. There are so many applications and so many places to go look for updates that it can be time consuming and a pain just to make sure everything is okay and working properly.

With a Mac, you no longer have to search and search for product updates because of a repository tool like MacUpdate Desktop. This tool will scour your machine for every app you have installed and then check its database for updates or patches that are available to you. You can then download and install all of the updates or individual ones if you so desire. Installation of the patches are seamless and do not require to be an IT person in order to make it work.

For $20 a year, this is a great tool that will keep your apps up to date and protected from any security vulnerabilities that may be out there. The database is constantly being added to so if your favorite app is not supported it will be soon. Currently there are over 30,000 apps in the database and I highly recommend this app to any Mac user.

Increase the number of telnet sessions allowed

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Thu, 03 Dec 2009 14:37:00 +0000

Increase the number of telnet sessions allowed

Again a default setting that I do not understand. An application that I support uses telnet for remote access (don't ask!) and by default the number of instances configured to be allowed to the box is 50. This is a fully patched and up to date Redhat 5.4 system.

In order to change this to something a bit more sane, you need to edit /etc/xinetd.conf and change:

instances = unlimited

You then need to restart xinetd by doing:

/etc/init.d/xinetd restart

SNMPD syslog entries

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Wed, 02 Dec 2009 22:04:00 +0000

Red Hat Knowledgebase: How can I fix the excessive logging of snmpd in Red Hat Enterprise Linux 4 update 5?

When you install Redhat Linux snmpd logging is cranked way up for syslog which can start to fill up your /var/log/messages file fairly quickly if you are using some sort of network monitoring software such as Orion. I personally don't want to see all of the snmpd connections coming to my server so you need to tell the snmpd daemon not to log extensively to syslog.

In /etc/init.d/snmpd, you need to change the options to be:

OPTIONS="-Lf /dev/null -p /var/run/snmpd.pid -a"

I am not sure why this is enabled by default on the latest net-snmp package but nevertheless this will fix the issue.

Adding Swap Space to a Linux server

rickyjmitchell@gmail.com (Rick Mitchell Solutions) — Wed, 02 Dec 2009 21:50:00 +0000

Adding Swap Space

Obviously swap space is bad and should be used as a last resort to physical memory. However, there will be times when you will want to add swap space to a server that needs an additional area or an increased size due to application requirements.

The link above is a good overview of increasing the size of a logical volume that happens to be formatted as swap. I used this recently to increase the size of swap for a server from 20gb to 60gb on a Redhat 5.4 64bit server.