藍色情懷

神勇的 FreeBSD



有位仁兄將原本的雙 P3 (跑 Linux) 換成雙 Xeon, 原本需要跑 17 小時的程式只要 5 個多小時就跑完了. 聽起來不賴, 但在好奇心的驅使下, 他將同樣的機器灌了 FreeBSD 跑同樣的程式, 結果令人驚訝的是, 在 FreeBSD 上只花 44 分鐘就跑完相同的程式 ! 

The beginning of the good news, for me at least. After installing everything and running the previously mentioned process, there was something very hard to believe. In the same box, with the exact same hardware configuration:

Debian+linux 2.6.9 + raid tools + XFS + PostgreSQL 7.4.6 = 5 hours 30 minutes
FreeBSD 5.3 + gvinum + UFS2+S + PostgreSQL 7.4.6 = 44 minutes

Clearly there was something very wrong here.

There wasn't.

不知道是怎樣的程式 ? 也許跟 FS 有蠻大的關係..

Free Software in Corporate Environments
There has been some adoption of free software lately at my current job. I'm not talking about the servers running apache, postgresql, samba, postfix, squid, etc. I'm talking about free software in everybody's computer. Note that everybody (but me) is still using Windows, but hopefully once they all use free software a migration to Linux will be painless, since people use applications and not operating systems.

The first free software application used around was the most obvious: Firefox. It started by word of mouth. It is faster, safer, smaller, it blocks popups. People love it. Not everybody is using it but still, it's an spontaneous move, nobody is forcing them to do it (there was a squid rule for a couple of users with lots of spyware problems that forced them to use firefox, but it's gone now).

Now the second move was an official one: OpenOffice.org. This is the BIG money saver. Microsoft Office costs A LOT of money, and most people just use Outlook and the most basic features of Word. Excel is used mostly to store lists of stuff, not as a spreadsheet.
Management gave me the freedom to prepare an OpenOffice migration. And it has been a success. Right now almost half of the people around here is using OpenOffice instead of Microsoft Office. Note that I installed the 2.0 beta. It has an excelent quality, is VERY stable, and the users love it (once they get used to the fact that it takes longer than MS Office to load). Disabling Java and tweaking the memory settings helps A LOT.
In the first days I gave a "migration talk", I prepared some case uses and everybody noted that the way oo.org works is very similar to MS office. What I didn't expect was a general concern: How to setup keyboard shorcut keys. I was in trouble, I didn't know how to do that. So I was honest and I told them the truth, that I didn't know how to do that but we can use the search feature in the help system and we immediatly found what we were looking. Props to the OpenOffice.org documentation project for this, it saved my day.
Real non-geek-final-users are using oo.org here. It is an excelent product.

But there is something that Microsoft Office has that OpenOffice.org doesn't: Outlook. Final users love that buggy piece of crap. Sysadmins and helpdesk people hate it. I hate it. It's buggy, sometimes it refuses to work and it has a lousy security record. I want it (and Internet "explorer") outside my nework. But I just can't say "don't use outlook anymore", I must come up with an alternative. At the time I was using Evolution to test the "linux-final-user experience" (I am a disciple of the mutt order). But evo has a serious problem: it doesn't run on windows (at least not yet). So I had two choices, both from mozilla: Thunderbird and the Mozilla suite (codename seamonkey). I tested both in my debian workstation and allthough I really liked thunderbird, I fell in love (again) with the Mozilla suite. I loved the integration of his parts: a (mature) web browser, a (mature) mail/news client, an excelent html editor, and a calendar application. It is every sysadmin's dream for his users. But I chose Thunderbird instead because:

Mozilla is devoting all it's efforts in the "birds-suite" : firefox, thunderbird, sunbird (firefox used to be a bird: phoenix/firebird). And now it is official, the mozilla suite won't have a new release. The birds suite is the way to go.
Outlook stores all it's junk in .pst files. Both Thunderbird and Mozilla Mail can import .pst files, but only Thunderbird could import the attachments of the messages. We have a winner.
And of course, Thunderbird is the tool of choice if you have spam problems (and who doesn't). It has a built-in bayesian filter that WORKS(tm).

On the server side, FreeBSD is taking over the server room. But this belongs to another post…

Posted in General, Computers, Debian, Free Software, FreeBSD | 3 Comments »

PostgreSQL, FreeBSD, SMP and vinum

Friday, February 4th, 2005
Today I'll talk about this very important PostgreSQL server. It was running RedHat Linux 7.x on a dual P3, and a process that sometimes runs there usually took like 17 hours.

There was a spare Dual Xeon laying around, so I decided to replace that old server. Obviously my first choice for a sensitive database server was Debian GNU/Linux, so I installed Debian Sarge to test it: kernel 2.6, PostgreSQL 7.4.6 and scsi drives in software raid-0 (striping) in XFS. Everything was perfect, and the process that took 17 hours in the other box took only 5:30 hours in the new box. A big improvement.

But I am a curious person.

Since there was no hurry to replace that old box (other than the performance since besides the 17 hours process it serves a high-traffic website), I installed FreeBSD 5.3 in that same Dual Xeon.

It was hell.

First, I had some experience with FreeBSD since Aureal System's server is running it. I have administrator access to the server but I had no experience:
- Installing FreeBSD (this was a piece of cake)
- Making software RAID work (this was HELL)

Now, I have read Michael Lucas' Absolute BSD and Greg Lehey's Complete FreeBSD. Lehey's book has nice chapter about Vinum, FreeBSD's Raid volume manager (Lehey is vinum's author after all), but there is a problem with vinum, freebsd5 and SMP (I was installing it in a Dual Xeon remember?). I tried 5.2.1, same problems. Finally it worked with an obscure and undocumented version of vinum called gvinum. The g stands for geom-aware. It worked.

But this was just the beginning.

The beginning of the good news, for me at least. After installing everything and running the previously mentioned process, there was something very hard to believe. In the same box, with the exact same hardware configuration:

Debian+linux 2.6.9 + raid tools + XFS + PostgreSQL 7.4.6 = 5 hours 30 minutes
FreeBSD 5.3 + gvinum + UFS2+S + PostgreSQL 7.4.6 = 44 minutes

Clearly there was something very wrong here.

There wasn't.

I ran the process again and again and the results were similar. I don't know exactly if this extraordinary performance gain in this particular process is because of the filesystem or the raid handler, probably it's because of both. I'll have to perform some serious benchmarks here, and publish the results of course.

The end of this story is:
- The FreeBSD server is now in production, it runs like a charm and the web pages that access the database now run almost 6 times faster than with the old dual P3.
- I'm installing more FreeBSD boxes.
- I'm reading McKusick's The Design and Implementation of the FreeBSD Operating System (thanks Breno) and Absolute OpenBSD.
- I am still running debian (unstable) on my desktop boxes, and probably this will not change.

Oh, and I'll use that SCSI powered dual P3 for my benchmarks, to be published here in a near future.

I just can't believe I've been avoiding BSD so many years.