I’ve got some performance problems with a mail server that’s using DRBD so I’ve done some benchmark tests to try and improve things. I used Postal for testing delivery to an LMTP server . The version of Postal I released a few days ago had a bug that made LMTP not work, I’ll release a [...]
I have released version 1.96 of Bonnie++ in the experimental branch .
The main changes are:
Made it compile on Solaris again (version 1.95 broke that) Now supports more files for the small file creation test (16^10 files is the limit), and it handles an overflow better. Incidentally this will in some situations change the [...]
Almost two years ago I blogged about a strange performance problem with SATA disks . The problem was that certain regions of a disk gave poor linear read performance on some machines, but performed well on machines which appeared to be identical. I discovered what the problem was shortly after that but was prevented from [...]
I have just released version 1.03e of my Bonnie++ benchmark . The only change is support for direct IO in Bonnie++ (via the -D command-line parameter). The patch for this was written by Dave Murch of Violin Memory . Violin specialise in 2RU storage servers based on DRAM and/or Flash storage. One of their products [...]
I’ve just started work on a new HP server running RHEL5 AS (needs to be AS to support more than 4 DomU’s). While I still have the Xen issues that made me give up using it on Debian  (the killer one being that an AMD64 Xen Dom0 would kernel panic on any serious disk [...]
I have just been running some ZCAV tests on some new supposedly 1TB disks (10^40 bytes is about 931*2^30 so is about 931G according to almost everyone in the computer industry who doesn’t work for a hard disk vendor).
I’ve added a new graph to my ZCAV results page  with the results.
One interesting [...]
The way Xen works is that the RAM used by a virtual machine is not swappable, so the only swapping that happens is to the swap device used by the virtual machine. I wondered whether I could improve swap performance by using a tmpfs for that swap space. The idea is that as only one [...]
Today I released new versions of my Bonnie++  benchmark. The main new feature (in both the stable 1.03b version and the experimental 1.93d version) is the ability of zcav to write to devices. The feature in question was originally written at the request of some people who had strange performance results when testing SATA [...]
As correctly pointed out by cmot  my previous post about software RAID  made no mention of bus bandwidth.
I have measured the bus bottlenecks of a couple of desktop machines running IDE disks with my ZCAV  benchmark (part of the Bonnie++ suite). The results show that two typical desktop machines had significant [...]
Dear lazyweb, I want to design T-Shirts for my Bonnie++ and Postal projects. But representing those projects in a picture seems more difficult than SE Linux (see one of my SE Linux T-Shirt designs below). If you have any conceptual design ideas then please let me know.
Here are my current designs for SE Linux [...]