Changing RAID levels on Dell PERC or other LSI controllers

I recently had to switch a couple of backup servers running FreeBSD 10.3 from having their root filesystem on a RAID1 array to a RAID6 array spanning six disks, as we'd found the space offered on a two disk RAID1 insufficient for a few corner cases. The internet is full of MegaCli cheat sheets, but none of them had the full set of info. Here's what I did to add the four new drives and convert the setup to RAID6:

# Add the four new drives to the existing array
MegaCli -LDRecon -Start -R1 -Add -PhysDrv \[32:2,32:3,32:4,32:5\] -L0 -a0

Living with the Samsung SSD T1

I found myself short on space on my work laptop recently, and as the majority of space was taken up by things I'll only need when at the office, it seemed a decent solution to add an external drive for those things.

Scouring the interwebs for a USB3 drive with good performance and a decent form factor lead me to pick the Samsung SSD T1. As a Linux and Mac user, I was not expecting any problems or quirks with an SSD from an established manufacturer like Samsung. Boy was I ever wrong...

Oh iPad 2, you so cool...

Ever since iOS 7 was launched, I've been having issues when upgrading my iPad 2 to the latest patch. The usual ones that many people have reported - spontaneous reboots, reboot loops on restores, iOS plain refusing to update when using OTA updates. I've read many speculations that Apple included some sort of load test to catch iPads with hardware issues that would prevent a good user experience, and whether that is correct or not, the solution I've found seems to confirm that hardware temperature at least plays a part.

On hardware replacement strategies and sleep

Over the past year, my place of employment has had the opportunity to change a lot of our alert handling procedures, not least when it comes to hardware, and that has been the cause of a lot of very nice changes for those of us in the trenches. In short, we have moved from reactive to proactive where it matters, which means we get to sleep at night even when on call.

Thoughts on tools

As the timeline of my posts clearly shows, the last few years have featured absolutely no new posts here. Much of that has to do with tools. The right tools makes a huge difference to productivity and to what time is spent on, and sadly, these last few years it has occasionally felt like I've spent more time fighting my tools than being productive.

A CMS by any other name...

Changes are afoot at my little abode on the interwebs, first of all I've decided to ditch Wordpress for Drupal and to change my primary domain for this little collection of random ramblings. I'm also half-stride in a server move and many other changes, great and small.

A strange take on physical security

During my time as a consultant I've seen many interesting takes on security. Today has been no exception. When visiting a client, we found that a new security policy has been enforced. In order to ensure that only authorized personnel and invited guests are in the building, they now require that guests are wearing guest access cards.

Slow writes to RAID on Dell PowerEdge SC440

Every few years I come across one of the little boxen, and every time I face the same issue. I can clearly remember that the RAID is slow for a reason, just not which reason. This posting is intended to save me from spending time on google in a few years... The Dell PowerEdge SC440 is a nice little Xeon-based tower server featuring a SAS 5/iR RAID controller. The sluggish writes are due to the default disabling of write cache on the controller, which is just fine for making sure data are not lost if the power fails, but which also drags performance down to ridiculous levels.

iChat video chat behind PF/NAT

I recently had the opportunity to fiddle a bit with getting iChat video chat to work properly with PF and NAT. As we all know, NAT is evil - getting ugly protocols past it no less so. First step in finding out exactly what went wrong was doing a bit of tcpdump on the internal firewall interface while trying to connect to a video chat session:
1235401525.872542 > udp 16 1235401526.060152 > udp 16
So far so good, the connection to the SNATMAP service at Apple worked nicely.

Using the Solido Systems spamfilter with OpenBSD

From the capable minds and hands of Solido Systems I got a license key for the spamfilter they make, and just had to try it on my OpenBSD 4.4 server. The filter is a java app with a spamasssassin plugin, and with java 1.7.0 included in the package list for 4.4, the time was right for testing - I'd previously had (and lost) quite a few fights with java from ports on 4.2 and 4.3.


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