Cluster fencing – Unlike many common thoughts, high-availability is not the highest priority of an high-availability cluster, but only the 2nd one. The highest priority of an high-availability cluster is maintenance of data integrity by prevention of multiple concurrent access of nodes to the shared disk. On different cluster, depending on the vendor, this can…
Actually, this post has become less of the non-technical type and more of the technical type, however, for the sake of the cute little Nabaztag (you can send me messages too! Go here and send a message to “fatutchi”!), I keep it still in this category as well. Today is a busy day, so I’ll…
I have received my Nabaztag/tag just a day ago, and it is a cute little thingie. At-ten-tion! What can it do? Actually, not much. It is a wireless device (client) which access Violet’s Nabaztag servers to get its commands. You, theoretically, cannot hijack the session and use it directly over LAN, but you must go…
Modern Linux LVM offers great abilities to maintain snapshots of existing logical volumes. Unlike NetApp “Write Anywhere File Layout” (WAFL), Linux LVM uses “Copy-on-Write” (COW) to allow snapshots. The process, in general, can be described in this pdf document. I have issues several small tests, just to get real-life estimations of what is the actual…
I’ve had a belief for quite a while now that Linux, unlike other types of systems, was unable to produce any I/O SNMP information. I only recently found out that it was partially true – all production-level distros, such as RedHat (and Centos, for that matter) were unable to produce any output for any SNMP…
Most modern servers use Broadcom network cards. The module is called tg3 and is known to have issues. You can find in my blog several posts about weird problems with tg3. This post is about another one I’ve encountered only recently. The server: Dell PowerEdge (PE) 830. Linux version: RedHat Advanced Server 4 (RHEL4) Update…
