Comparison between reiserfs and ext3

Recently, I just switched from the reiserfs File System to the ext3 log file system. I am a loyal follower of reiserfs and have not changed my views on this file system until now. The reason why I switched to ext3 was that I wanted to spend some time looking at what I liked in ext3. Ext3 is a log file system developed by the Free Community. It is designed as an upgrade version of ext2 to facilitate migration from ext2 to ext3 as much as possible. On the basis of ext2, ext3 adds the logging function of metadata, and strives to maintain forward and backward compatibility. Therefore, it is more appropriate to call this file system the new version of ext2. Reiserfs is developed and developed by the development team under the leadership of Hans Reiser. SuSE Linux also plays a major role in its development. Now, it has developed into an efficient and reliable file system.
Reiserfs is different from ext3

In terms of technology, there are many differences between the two file systems, but for most people, you only need to pay attention to the points. First, you can easily upgrade from the ext2 format, because so far, many Linux distributions are still using this file system. The second is that ext3 not only records data logs (which is already available in ext2), but also records metadata logs. The current reiserfs only has the log metadata. The third is the scalability of the file system. Before introducing the third point, let's take a look at the first two differences, because the third point deserves our special attention. As far as ext3 is concerned, it is a major advantage to easily upgrade and convert the ext2 file system. Of course, this is meaningless for people who have been using reiserfs. However, most users are reluctant to try any log file system other than ext3. The reason is simple. Converting ext2 to ext3 is simpler and faster than converting to any other file system.
Compared with ext2, ext3 provides better security, which is the difference between data logs and metadata logs. On two different computers, one uses data logs and the other uses data and metadata logs. Start some applications, make appropriate changes to some data files, and then turn off the power. When the first machine is started, it can quickly restore the file system to a stable State. However, the changes you made to the data file have been lost due to power loss. The second machine can quickly restore the file system to a stable State and retain all the changes you made to the data before power loss.
Obviously, most computer users prefer the latter. However, you should consider it carefully unless you have such a requirement. When metadata logs are added to data logs, the system speed is severely affected. In most cases, reiserfs is much faster than ext2 without the log function. In addition, in general, reiserfs is much faster than ext3 with the metadata log function. If you select both the data and metadata log functions, the reiserfs is much faster than ext3.

Speed is not the key to selecting a File System

As mentioned above, reiserfs is much faster, but in reality, people are often not concerned about speed (I mean it is not a particularly obvious speed difference ). As a user, it is hard to imagine that it takes 2.5 seconds or 4 seconds to open a Word file or an Excel form. In fact, most people choose to use Microsoft's office, not based on speed, but because everyone is using this office suite.
This phenomenon not only occurs in the Windows Field. Kword or abiword is much faster to load than StarOffice. However, many Linux users are still admiring it while waiting for StarOffice to start slowly. Generally, they will not give up StarOffice because of its low speed, because they are used to it.
It can be seen that although the speed is slow, as long as it is still within the limits that people can tolerate, the average person will not mind. We generally like to blame hardware for the slow speed, rather than software. For example, many hardcore game players generally purchase the latest chips and graphics cards to run their favorite games, rather than buying running games based on their existing hardware configurations.

Here, I must clarify that I do not think that because faster processors and larger memory can be used, therefore, Linux can adopt very slow and bloated program code (of course, Linus Torvalds won't promise to do so ). I just think that when doing something, you can take or choose a suitable method to do it. If someone wants to enjoy the data log security function provided by ext3 and does not want to lose speed, you can buy a faster processor to make up for the shortcomings of the file system.

Of course, the reiserfs file system has similar problems. Therefore, if you want to use reiserfs and worry about data loss, you can disable the write buffer function of the drive. Depending on the system in use, the command to disable this function may be different, but it may be similar to the following command:

/Sbin/hdparm-wo/dev/had

The above command is to disable the write buffer function of the first ide drive in the system. Note that this will greatly affect the system performance. Of course, since you can tolerate the decline in the system speed caused by the ext3 metadata log function, why? On my machine, for fear of losing some important data, I disabled the write buffer function for one of the drives, and the performance dropped sharply, but I think this price is still worth it.
After talking about this, I just want to explain one thing. That is to say, for most people who use computers, selecting reiserfs or ext3 is not a decisive factor in speed. Only a few users and some special environments with extremely strict speed requirements will care about the speed difference between the two. In addition, ext3 has a unique feature that allows users to control data logs at each load point. In other words, you can load multiple partitions from a drive, and each partition can decide whether to use the data log function. Of course, if the write buffer function of the entire drive is disabled, this option will not be available.
In reality, most people do not consider performance or security, but always want to adopt the most convenient and familiar way. In the selection of various channels, a decisive factor is the system that the user is currently using. However, in the Linux suite that we choose to use in the future, whether you reinstall or upgrade the file system, various Linux distribution companies will make the selection process very simple.

File system scalability

Now let's take a look at the key third factor: scalability. If you visit the reiserfs site (http://www.ReiserFS.org/), you will find that reiserfs is very concerned about space utilization and speed, so it is very good in disk utilization and performance. When I switched the file system from reiserfs to ext3, I found that my available space was reduced. However, this does not matter, because the current disk space and memory prices are very low. In addition, reiserfs has made great efforts in balancing trees. Reiserfs is a file system structure based on the Balance Tree, which makes it much better to process massive file systems, such as file systems on servers.
What highlights reiserfs is that it is designed to implement some future plug-ins that provide access control lists, hyperlinks, and other very good functions. At this point, the developers of reiserfs are better than ext3, because they have already considered the functions to be implemented in advance. In this way, the stability of these features must be better than that of ext3. According to data, no one planned to design the log function for ext2. The log function was quickly supplemented later. Of course, this is not a bad thing, but at least when you use it, there will always be an insecure feeling. Therefore, it would be wise to choose reiserfs if you focus on future scalability considerations.

In general, these two file systems are both excellent, and no one has an absolute advantage to overwhelm the other. If you are using an ext2 file system with high data security requirements, consider using ext3. If you are more concerned about the speed and scalability of the file system, or want to try to use a file system other than ext2, then reiserfs should be the first choice.