It appears in some cases, for some pieces of software (anyone said “open source and poorly documented?”) that every installation has its own quirks and issues. It seems that following the same pattern is not always enough. It can be caused by the day you have selected to download and use the external component which…
I have demonstrated how to hot-add LUNs to a Linux system with Qlogic HBA. This has become irrelevant with the newer method, available for RHEL4 Update 3 and above. The new method is as follow: echo 1 > /sys/class/fc_host/host/issue_lip echo “- – -” > /sys/class/scsi_host/host/scan< Replace "<ID>" with your relevant HBA ID. Notice - due...
Sysstat package, for me, is a must on any Linux machine I get to deal with. It allows for easy collection of performance data, and it allows easy postmortem of past (short past, anyhow) problems. For me, the only change from RHEL4 defaults is by setting the time interval to one minute, in stead of…
This is a rather common knowledge now that on RHEL4 you need to state inside /etc/modprobe.conf the following line, when you want more than one bonding interfaces: options bonding max_bonds=2 Then you attempt to use a trick to address different bonding devices with their name (aka, bond0 and bond1, and maybe bond2, etc), using an…
Linux works perfectly well with multiple storage links using dm-multipath. Not only that, but HP has released their own spawn of dm-multipath, which is optimized (or so claimed, but, anyhow, well configured) to work with EVA and MSA storage devices. This is great, however, what do you do when mapping volume snapshots through dm-multipath? For…
I was required to write a small listener. This listener doesn’t have to do anything fancy – it has to process input from a network source (over TCP) and shove it into a file with random name. The quick and dirty solution is to use netcat (nc). A short command such as this would do…
