Why … oh … why …

Dear Red Hat: You put out a good product in RHEL 6.x. Ignoring the (often massive) performance regressions, other things are better/more stable. Dracut, is growing on me. Actually liking being able to debug startup. But, this said … I have to inquire … Why on earth did you include an End-Of-Lifed version of Perl […]

RIP Kyril Faenov

Kyril Faenov of Microsoft passed away several days ago. He was one of the visionaries and leaders behind Microsoft’s HPC effort. He was also a nice guy, one whom I had a chance to talk with several times over the last few years. One of the bright folks you like to challenge. I respected him […]

Misalignment of performance expectations and reality

We are working on a project for a consulting customer. They’ve hired us to help them figure out where their performance is being “lost”. Obviously, without naming names or revealing information, I note something interesting about this, that I’ve alluded to many times before. There is an often profound mismatch between expectations for a system […]

siFlash tuning

We’ve been tuning our siFlash. Not done yet … not done, but look where we are. 24 simultaneous streaming (non-cached) reads. Run status group 0 (all jobs): READ: io=193632MB, aggrb=<strong>7781.4MB/s</strong>, minb=7781.4MB/s, maxb=7781.4MB/s, mint=24884msec, maxt=24884msec Yeah. Baby. Added another almost GB/s to the read performance. Streaming write performance is hovering around 2.6GB/s. Remember, this is a […]

What high performance isn’t

We’ve had a number of interesting interactions with customers over the last few weeks. They all seem to center on, and around, how to get high performance out of gear which isn’t designed for high performance. Generally speaking, you can’t. High performance requires a mixture of design and implementation, with well designed and implemented parts. […]

An NFS gotcha

As we rebuild our server infrastructure (aside from taking time to do things more intelligently), we run into some bumps. This one sorta threw me for a bit. [root@virtual ~]# mount -a mount.nfs: Stale NFS file handle mount.nfs: Stale NFS file handle Checked all the usual suspects. No dice. The /etc/exports was correct, and visible […]