Link: IRON File Systems

IRON File Systems [PDF] is apaper from the 2005 ACM Symposium on Operating Systems Principles.To quote from the abstract:

Commodity file systems trust disks to either work or fail completely,yet modern disks exhibit more complex failure modes. We suggest a newfail-partial failure model for disks, which incorporates realisticlocalized faults such as latent sector errors and block corruption.We then develop and apply a novel failure-policy fingerprintingframework, to investigate how commodity file systems react to a rangeof more


A Solaris 8 Disksuite single user mode surprise

If you boot a Disksuite-using Solaris 8 machine into single-user modeto do maintenance and do a metastat , you'll discover that all of yourmirrored metadevices are marked as needing to be metasync'd, even ifthey actually are fully consistent.

What seems to be going on is that Disksuite doesn't update thingsfrom the on-disk metadata state database when the kernel bringsup the metadevices themselves in early boot. Instead, it defers thisuntil you explicitly run ' metasync -r ',


I hate hardware (AMD CPU edition)

I have been trying to spec out a new machine lately, which is remindingme all over again how I hate hardware. This time around, the target ofmy particular hate is AMD CPUs, especially the new AM2 ones, where theperformance picture has become so complicated that you need a largechart to understand it.

Choosing CPUs used to be simple: within a given CPU family, the onlything that changed performance was the clock speed, so you could justbuy the fastest CPU your budget and desires afforded


菊花台

最近在聽周杰倫的新碟《依然范特西》的歌,老實說其實跟他其他的專輯差不多,所有的歌曲都可以找到之前作品的影子。不過這並不緊要,我就是想聽周氏曲風,只此一家的東西。

聽慣了周杰倫,都知道咬字不清算是他的個人


Industrial strength Python

It's not uncommon to have people harsh on Python and similar languagesas being 'scripting languages', not suitable for serious jobs becausethey're not fast enough or they use too much memory, or the like. I haveto beg to differ, because I have a great counter-example.

We use a SMTP frontend daemon to check connections before we bother tostart a real SMTP conversation. This program does our greylisting, ourDNS blocklist checking, connection count limiting, and a number of otherchecks


Some wise words from Henry Spencer on backups

Henry Spencer recently wrote some very useful words of advice on backupson a local sysadmin mailing list. They struck me as the sort of thingsthat are useful enough to share more widely, so with Henry's permissionI'm putting his message here. (I thought about running just part of hisemail, but the more I read it, the more I wanted people to see all ofit, so I'm just going to put up the whole thing.)

So, in Henry Spencer's


決戰時刻.每當變幻時

辦戶外活動,遇著驟晴驟雨的天氣,最是頭痛。不過既然可以做的都做了,後備計劃也有了,就看上天安排,這樣也可以印證另一種意義吧。

昨晚在“信報”讀到Spencer Wong的談廣告業的文章<人在變 變在人>,覺得很妙,很有“親切

1.
明天開始,隔週的四、五、六,在明報世紀版會有一個小角落,有一個叫「斑駁日常」的方格。本來以為3-400字是我的極限了,但那天黃茂林還叫我寫些3-40字的。

2.
這個好東西 我一定會去,但一直很忐忑好不

How fast an LCD refresh rate is going to be fast enough?

One of my small peculiarities is that I'm an old-fashioned CRT person.By now this is an unfortunate affliction since it's pretty clear thatLCDs are the future, whether or not I really like them. (If the pricesfor good CRTs haven't already bottomed out and started climbing due todecreased production, it probably won't be long.)

Part of the reason I haven't warmed to LCDs is that they have scary andvisible failure modes, like stuck pixels, that


決戰前夕.雜感

新時代
新賭場開幕,其大陣仗是小城罕見的,前一陣子當局公佈小城的人口已超過50萬,媒介又說這樣的人口數字已經是大城市的規模,可是我們這些澳門街的居民,真的可以接受澳門街在幾年之間變成大城市嗎?年輕人尚且