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Problems with SATA disks and Dell PE SC1435: how to fix
We have got a couple of Dell PowerEdge SC1435 (Dual Opteron) with a lspci output like this: 00:01.0 PCI bridge: Broadcom HT1000 PCI/PCI-X bridge 00:02.0 Host bridge: Broadcom HT1000 Legacy South Bridge...
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Keepalived and TCP_CHECK problem
Today I was debugging a problem I had with keepalived not discovering that a real server behind a virtual IP it manages, had died. The problem was really strange because the check was very, very simple...
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Using Wanem to simulate a wide-area network
If you (or your company) are in the web-development business, one thing you need when testing your application, besides trying it in different browsers, is trying the user experience at differents...
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FreeBSD6 and nfsd gotchas
If you’re using FreeBSD6 as NFS server, you may find useful these quick tips related to /etc/export syntax, because otherwise you will be stuck with a generic mountd[321]: bad exports list in your...
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*fdisk and the 1.5TB partition size limit
If you have a large volume (like a disk array or the next-generation SATA disk) and you’re trying to create a single, giant partition for whatever reason, you should know that fdisk (for DOS...
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Note to self: accessing LVM volumes from live CD
If you have a Linux machine with LVM volumes on it, and you need to boot it from a live CD (for example SysRescueCD) and you wonder where your volumes are, just issue (in an LVM enabled system, of...
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PHP 5.3 max_input_vars and big forms
Starting from PHP 5.3.9 there is a brand new php.ini option: max_input_vars. You may read in the PHP documentation about it. But what you don’t probably now is that if you are using the Suhoshin patch...
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Very slow Hadoop on PowerEdge R815
We have a little internal Hadoop cluster for development and testing, two very powerful Dell PowerEdge R815 with Debian and a bunch of Xen VMs to reproduce a production environment. Problem is that the...
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Xen, XFS and the barrier error
Probably nobody is going to hit this but since I’ve lost half a morning puzzling my mind about this error, I think it would be useful to blog about it. We have some old Xen machine running Debian Lenny...
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nginx and the too many open files limit
So, nginx is fast, nginx is light, nginx is great but… nginx can be nasty too, with undocumented unexpected behaviors. What happened today? We were putting in production a new reverse proxy based on...
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