New stats in iostat

Recelnty I've noticed that iostat (for RedHat sysstat-9.0.4-31 version) reports new fields: r_await and w_await.

Following online documentation: this stands for:

The average time (in milliseconds) for I/O requests issued to the device to be served. This includes the time spent by the requests in queue and the time spent servicing them.

Why update to newer versions - munin

Ppl tend to not update their software. There is a rule "If something works, do not touch it". But this rule is not true.
Lately I've update munin to version 2.0.19-1, and after checking performance of my kvm nodes I got really surprised. CPU usage for host which is mostly generating munin raports dropped from 23% to about 12%, which means that new version is 2 times faster!!!
All nice cpu usage on the graph is munin.

Another look at amazon EBS storage performance

Lately I've gave up bonnie++ in favor of iozone. I've done lot of performance checks on hardware I've got in my hands. That also means that I have to check iozone performance on my amazon instances.

Since tested instance was t1.micro, 1Gb test file was enough to avoid false cache results.

So command run was:

./iozone -a -i0 -i1 -i2 -r4k -O -n1g -g1g

Quick look at amazon EBS / instance storage performance

Lately I've been testing amazon EC2 and moving my virtual machines there. So I got a chance to test some EBS / instance storage block devices.

And my t1.micro instance got EBS performance like this:


And as you can see, this performance is not amazing. Slow writes, slow rewrites, nice reads (but still slower then 7200 rpm hdd). So you can't expect fast IO from t1.micro. But what amazes me is seek amount, almost like ssd storage. Strange but true. Of course those results varies on (I guess) resources available.

LUKS and intel aes-ni performance part 2

Lately I've bought laptop with Intel i7-3720QM. Laptop got 2 disks: SSD Vertex 120GB and original WD Scorpio 7200rpm hdd. I have to check LUKS performance of this setup ('cause I use LUKS on daily basis). And it looks like this (of course bonnie++ results):

HT on, WD Scorpio 320GB 7200rpm, lvm, ext4, no encryption:

Usb2 vs usb3 under linux

Lately I've been buying laptop for myself. And was wandering if I need one with usb3 ports. I've already got usb3 mobile 2'5 hdd, but I've thought that 5400rpm hdd doesn't really need usb3. Finally I've got laptop with usb3 so I have to run some tests ;).
Used bonnie++ on hdd connected to usb3 port and usb2 port. Here are results:



In quest of perfect laptop

Lately (for like 3 years), I've been looking for perfect laptop. I've been using 10+ of them during that period owned two, having three company ones. One of company laptops was almost perfect.
What is perfect laptop for me? Having those features:
* cpu with virtualization (to let me use windows VMs),
* cpu with AES (to let me use my luks crypted disks without loosing too much performance),
* gpu with vdpau support, which means nvidia card (with at least pure video feature set C),
* fast 300GB+ hdd – 7200 rpm, hybrid or ssd,

Bonnie++ results database

Finally I've just found small amount of time to write 2 PHP scripts and create database with all bonnie++ results I've got. All tests were run by me. Some tests do not have character speeds (those got -1 value there). You can sort results by: block write speed, character write speed, rewrite, block read speed, character read speed and seeks. You can also narrow results down by filtering LVM, encryption and filesystem type. Every new bonnie++ runs gonna go there.

Hope some of you gonna find this useful. Link is

vSphere 5 hardware dependant iSCSI vs software iSCSI on Broadcom NetXtreme II 5709c

Recently I've been setting up vSphere 5 infrastructure with 2 iSCSI storages.

LUKS and intel AES extension performance

Finally I've just got cpu with AES-NI to play with. And finally I was able to check performance gain using hadrware with LUKS volumes.
Edit: most important info, tested CPU was Intel Xeon X5650.

First of all I've checked block device speed (which was 2 SAS 300GB RAID1 set) without encryption. Device has ext4 and I used bonnie++ as usual.



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by Dr. Radut