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Archive for the ‘operating systems’ Category

Using an OpenLDAP Proxy to Work Around Solaris/Active Directory Issues

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There is a long-standing bug in (Open)Solaris and derivatives (including NexentaStor) that breaks Active Directory interoperability:

Beginning with Windows Server 2003, Active Directory supports VLV searches. Every VLV search request must be accompanied by 2 request controls: the SSS control and the VLV control. However, Active Directory imposes some general criteria on the SSS control:

1. Cannot sort based on more than one sort keys/attributes.
2. Cannot sort based on the “distinguishedName” attribute (presumably Microsoft does not use the “DN” attribute).
3. Cannot sort based on a constructed attribute (presumably an attribute not stored on Active Directory).

Unfortunately, Solaris LDAP clients use 2 sort keys/attributes: “cn” and “uid” in the SSS control. Subsequently, when dumping a container or a naming database, Solaris LDAP clients would receive LDAP_UNAVAILABLE_CRITICAL_EXTENSION.

$ ldaplist passwd
ldaplist: Object not found (LDAP ERROR (12): Unavailable critical extension.)

This issue has been detailed elsewhere, including at utexas.edu. There appear to be at least four solutions:

  1. Wait for the fix from Sun Oracle to reach the light of day: this bug was apparently fixed in SNV 144. (I expect the fix is out in Solaris 11 Express now, but have not tested this myself.)
  2. Apply the hotfix in Microsoft’s KB886683 to your domain controllers, which will disable VLV.
  3. Run separate ADAM instances with VLV disabled, and point your Solaris machines at them instead of directly at your domain controllers. From the blog post linked above, it sounds like the University of Texas chose this route.
  4. Use OpenLDAP as a proxy in front of Active Directory; configure your Solaris machines to use the proxies instead of Active Directory servers. This is the solution detailed in this blog post.

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Written by Andy

January 6th, 2011 at 6:20 am

Installing the F5 FirePass VPN Client on Ubuntu 10.04 AMD64

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Disclaimer: I am not a FirePass administrator; only an end-user and have no other relationship with F5. There may be better methods to address this issue; please comment if you know of one.

See also: f5vpn-login.py, described here, and brought to my attention by sh4k3sph3r3. A CLI FirePass client is quite likely a better solution than separate browser instances, etc.

Preliminaries: Although the F5 FirePass SSL VPN product supports Linux, as best as I can tell, that support is somewhat limited: My understanding is that they officially claim support for 32-bit installs only, and they do not appear to track new distribution releases particularly aggressively. F5 has also been somewhat slow in supporting new browser versions: They announced support for Firefox 3 on October 6, 2008, nearly four months after its release and with only two months to go before Firefox 2 was end-of-lifed. For Firefox 3.6 support, a comment on the post linked above states that you need to request a special hot fix from F5 (which my site has not applied). There is no Google Chrome support that I am aware of.

Further, F5′s automated client installation tools have unfortunately never worked for me on Linux, even when the architecture and browser are in their support matrix. The manual download instruction links are also broken on the FirePass install I connect to.

Solution: Install a dedicated, 32-bit version of Firefox in a supported version; create a single-purpose Firefox profile for VPN use. Add the FirePass client to that browser and the operating system.
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Written by Andy

May 20th, 2010 at 11:12 am

Keeping your RHEL VMs from crushing your storage at 4:02am

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Running a lot of Red Hat VMs in your virtual infrastructure, on shared storage? CentOS, Scientific Linux, both versions 4 and 5, they count for these purposes; Fedora should likely be included too. Do you have the slocate (version 4.x and earlier) or mlocate (version 5.x) RPMs installed? If you’re uncertain, check using the following:

> rpm -q slocate
slocate-2.7-13.el4.8.i386

or

> rpm -q mlocate
mlocate-0.15-1.el5.2.x86_64

If so, multiple RHEL VMs plus mlocate or slocate may be adding up to an array-crushing 4:02am shared storage load and latency spike for you. Before being addressed, this spike was bad enough at my place of employment (when combined with a NetApp Sunday-morning disk scrub) to cause a Windows VM to crash with I/O errors. Ouch.
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Written by Andy

November 19th, 2009 at 12:39 pm

OpenSolaris 2008.05 on EC2 – Why 32-bit only?

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Since Sun and Amazon removed the limit on the number of OpenSolaris 2008.05 instances able to run on EC2, I’ve been curious – and a little bothered – by the fact that the 2008.05 AMI is 32-bit only. Curious because OpenSolaris shouldn’t have any issues running on a 64-bit EC2 instance (there are other 64-bit OpenSolaris AMIs available on EC2, after all), and a little bothered because there have been long-standing reports of trouble running Solaris on 32-bit architectures, which makes me hesitant to invest much effort in a 32-bit OpenSolaris EC2 environment.

Well, perhaps a 64-bit AMI is forthcoming – I think this is still a beta program – and perhaps Sun’s just trying to save us a buck or two, since the cheapest 64-bit EC2 instance is four times as expensive per hour as the cheapest 32-bit instance.

Written by Andy

August 18th, 2008 at 3:42 pm

Capacity Limit for OpenSolaris on EC2 no more

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According to a blog post on blogs.sun.com, the capacity limit for OpenSolaris 2008.05 on EC2 has been removed.

The blog entry makes it sound like you no longer need to register with Sun to use OpenSolaris on EC2, but that doesn’t appear to be the case – I only see the AMI in my private instances, and the details on the image seem to confirm this.
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Written by Andy

August 14th, 2008 at 2:27 pm

Posted in operating systems

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No Luck with a Quick-n-Dirty BFU of SXCE 79 on EC2

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For grins, I tried a quick-and-dirty BFU of a SXCE 79 instance running on EC2 to the latest nightly build this morning. I roughly followed Ben Rockwood’s BFU instructions and didn’t do anything to resolve conflicts beyond running acr. On reboot, it looks like the system panicked – I presume the reason is probably somewhere in here. Console dump after the jump for the curious.
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Written by Andy

June 25th, 2008 at 7:19 am

Posted in operating systems

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Putting Ubuntu on the Eee PC

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I finally got around to installing Ubuntu (Hardy) on my Eee PC this weekend. My only regret: That I waited so long to do it.
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Written by Andy

June 22nd, 2008 at 2:57 pm

Posted in operating systems

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Reading List, 6/4/2008

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  • Ubuntu Netbook Remix – “A ‘remix’ of the standard Ubuntu Desktop 8.04 release to enable it to work better on devices with small screens, such as Netbooks (sub-notebooks).” I’ve been meaning to replace Xandros on my Eee with Ubuntu – it’ll be nice to have this on top of Hardy Heron. (Seen at Ars Technica, whose post has more info and some nice screenshots.)
  • Internet Traffic Growth Doesn’t Matter – A look at Internet bandwidth consumption that sounds quite level-headed to me. A few great quotes, some of them excerpted from a presentation by Andrew Odlyzko: “Internet traffic growth rates are slowing. Hype is accelerating.” “Telecom is the only industry that worries about it’s [sic] customers using too much product.” “Volume is not value. SMS messages consume almost no bandwidth but bill out at $1000/Mb.” “Traffic growth simply doesn’t matter. Period. What matters is revenue.” And best of all: “Most people think they are special but in realty [sic] just want to watch ‘American Idol’.” (Seen at Data Center Knowledge.)

Written by Andy

June 4th, 2008 at 2:15 pm

Capacity limit on OpenSolaris 2008.05 AMI

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I missed this: Apparently the OpenSolaris 2008.05 AMI on EC2 has reached a capacity limit. So, while I got Sun’s approval this morning for their OpenSolaris/SXCE.79 on EC2 beta, I don’t get to use OpenSolaris until they add more capacity; SXCE.79 is a nice consolation prize, though.

Written by Andy

June 4th, 2008 at 11:27 am

OpenSolaris and EC2: Control Issues, Anyone?

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Generally, I’m a fan of Sun Microsystems. For the most part, I like their hardware and their software – and their best products show real innovation and willingness to take risks. I’m also a fan of Amazon’s EC2 product, so the announcement that Sun would be officially bundling OpenSolaris for EC2 was great news. Unfortunately, it seems that after all the hullabaloo, Sun doesn’t really want to make it that easy for you to actually use OpenSolaris on EC2, by managing access to it like a control freak would.
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Written by Andy

June 1st, 2008 at 8:58 pm

Posted in operating systems

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