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October 27, 2009

BeijingLSF 2009

Filed under: File System Magic,Great Days,kernel — colyli @ 12:31 pm

In the passed several months, I was helping to organize BeijingLSF(Beijing Linux Storage and File System Workshop) with other kernel developers in China. This great event happened on Oct 24, here is my report.

Since early this year, budget control happens in almost all companies/organizations, many local kernel developers in China could not attend LSF in United States (it’s quite interesting that most of kernel developers in China are storage related, mm, cgroup, io controller, fs, device mapper …). In such condition, we found there were enough people inside China to sit together for discussion on storage and file system related topics. In 2009 April, a proposal was posted on for BeijingLSF. Many people provided positive feed back, then we started to organize this event.

A 7 persons’ committee was set up firstly, people were from Novell, Intel, Oracle, Redhat, Freescale. The committee made a 20 persons’ invitation list. The website was built on and all invitees registered. Fortunately we got sponsorship from Novell China for soft drink and snack.

There were 6 sessions for BeijingLSF 2009. There was no talk, people just sat together to discuss on specific topics.

The first session was distributed locker manager. I led the session, the discussion included,

– introduced back ground of dlm, and current issues from fs/dlm (most of the issues were from my closed-or-opened and open-to-community BNCs).

– Oracle ocfs2 developers explained why ocfs2 using 64bytes lock value block.

– Jiaju Zhang (Novell) explained his patches for dlm performance improvement.

– Tao Ma (Oracle), Jiaju Zhang (Novell), Xinwei Hu (Novell) and I, discussed how dlm working with ocfs2’s user mode cluster stack.

The second session was clustering file system, led by Tao Ma (Oracle). Tao suggested people to introduce each other before the session. During the introduction, discussion happened when people introduced their current projects. When the discussion finished, 40 minutes passed. The workshop had no introduction time planed, therefore most time of this session was used for people to know each other. IMHO it was worth. This was the first time almost all storage and file system developers in China sat together, people came to know the faces behind email addresses.

The last session in the morning was shared storage and snapshot, led by Xinwei Hu (Novell). Xinwei introduced how logical volume management working in clustering environment, then discussion happened on,

– Considering snapshot start to happen on file system level, snapshot by device mapper might be less and less important in future.

– Is it possible to support snapshot by lvm in clustering environment and is it worth ? There was no conclusion from the discussion, and I’d like to hear from device mapper developers 🙂

After the lunch, the first session in the afternoon was VFS readahead and writeback. The session was led by Fengguang Wu (Intel), a 6 pages slide made people discuss for 90 minutes. Wu spent 20 minutes to introduce his patch, then people talked about,

– Why anonymous pages and file pages should be treated differently.

– In order to improvement writeback performance, MM should be able to suspend (maybe there is some better term) a process who making too many dirty pages.

– On some kind of SSD, linear read/write was slower than discrete read/write. If the storage media was SSD, there might be little difference for the writeback policy.

Second session in the afternoon was I/O controller and I/O bandwidth. The session was led by Jiangfeng Gui (Fujitsu). This talk was quite new to most of the attendees. Jianfeng explained the conception of io controller very well, at least I understood it was a software conception, not a haredware 🙂 io controller was an interesting idea, but most of concern in the workshop was focused on its complexity.

The last session of the workshop was interaction with industry. We invited an engineer from Lenovo – Yilei Lu, who was working on a internet storage solution based on Linux operating system. Yilei introduced how they used Linux as base system in their storage solution, what problems or difficulties they encountered. Many people provided suggestions to the questions, and most of the developers were very happen to hear feed back from the development users.

After all the six sessions, there was light talks. Almost all attendees said this workshop was the first effort to make upstream active developers to sit together in China. Some people showed their willing to sponsor BeijingLSF next year (if there is), some people said they could help to organize similar events in their cities. IMHO, BeijingLSF is a great and successful event. The most important thing is even not discussion, this is the *first* time for *ALL* (yes ALL) most active storage related developers within China to see each other, and have chance to talk face to face. Unlike LSF in United States, BeijingLSF has little effect to Linux storage and file system development, anyway it’s a great effort to make discussion and face-to-face communication happen.

Novell acts a very important role and contributes quite a lot to BeijingLSF. I was able to use the ITO (what a great idea!) to help organize BeijingLSF, and Novell China sponsored soft drink and snack to make all attendees more comfortable while talking whole day.

Finally please permit me to thank all attendees, they are,

Bo Yang, Coly Li, Fengguang Wu, Herbert Xu, Jeff He, Jeff Liu, Jiaju Zhang, Jianfeng Gui, Michael Fu, Tao Ma, Tiger Yang, Xiao Luo, Xinwei Hu, Xu Wang, Yang Li, Yawei Niu, Yilei Lu, Yu Zhong, Zefan Li, Zheng Yan.

Your coming and participating make BeijingLSF being a great and successful event.

Beijing Linux Storage and File System Workshop 2009

Beijing Linux Storage and File System Workshop 2009

[If you are interested on how the attendees look alike, please check]

October 16, 2009

My first publish

Filed under: Basic Knowledge,Great Days — colyli @ 11:53 am

After publish the Chinese translation of “Linkers and Loaders” on , this week the Chinese version of this great book is published. This is my first publish, though it’s a translation 🙂


If anyone finds any mistake from the translation, please send the errata to publisher or to me directly. I do appreicate for your feed back 🙂

[NOTE: the cover picture is copied from ]

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