vfs

It seems that the Linux VFS cache does not work by default with a FUSE filesystem. For example, the "read" call seems to be systematically forwarded to the FUSE filesystem. I work on a FUSE specific remote filesystem. I need a very aggressive cache. Do I need to implement my own page cache? Or is it possible to activate the Linux VFS cache for this particular FUSE filesystem? Or does someone know a good proxy/cache FUSE filesystem (or a kind of C library to do that without reinventing the wheel)? Bonus question: If I have to implement my own page cache, I think to use a REDIS daemon to do the

We are upgrading our application from JBoss 4 to JBoss 6. A couple of pieces of our application get delivered to the client in an unusual way: jars are looked up inside of our application and sent to the client from a servlet, where the client extracts them in order to run certain support functions. In JBoss 4 we would look these jars up with the classloader and find a jar:// URL which would be used to read the jar and send its contents to the client. In JBoss 6 when we perform the lookup we get a vfs:/ URL. I understand that this is from the org.jboss.vfs package. Unfortunately when I call

Is there a Java way to pre-allocate drive space for exclusive usage in the application? There is no requirement for this space to be a separate filesystem or a part of existing filesystem (so could easily be a database), but it should allow for reserving the specified amount of space and allow for random reads/writes with high enough throughput. You could try using a RandomAccessFile object and use the setLength() method. Example: File file = ... //Create a temporary file on the filesystem your trying to reserve. long bytes = ... //number of bytes you want to reserve. RandomAccessFile rf =

I am about to implement a custom VFS (virtual file system) for a Netburner embedded device (non windows) using FOpen, FRead, FWrite, FSeek, and FClose. I was surprised that i could not find a FOpen* version of the VFS available. It would make it a lot more portable to embedded devices. I found some information on creating the VFS for SQLite here http://sqlite.org/c3ref/vfs.html but the information is very detailed and I have lots of other questions about the implementation. I have some example VFS in the SQLite source code for Win, OS2, Linux but they don't have a lot of comments, only source

1 前言 自从诞生以来，Linux 就被不断完善和普及，目前它已经成为主流通用操作系统之一，使用得非常广泛，它与 Windows、UNIX 一起占据了操作系统领域几乎所有的市场份额。特别是在高性能计算领域，Linux 已经成为一个占主导地位的操作系统，在2005年6月全球TOP500 计算机中，有 301 台部署的是 Linux 操作系统。因此，研究和使用 Linux 已经成为开发者的不可回避的问题了。 下面我们介绍一下 Linux 内核中文件 Cache 管理的机制。本文以 2.6 系列内核为基准，主要讲述工作原理、数据结构和算法，不涉及具体代码。 2 操作系统和文件 Cache 管理 操作系统是计算机上最重要的系统软件，它负责管理各种物理资源，并向应用程序提供各种抽象接口以便其使用这些物理资源。从应用程序的角度看，操作系统提供了一个统一的虚拟机，在该虚拟机中没有各种机器的具体细节，只有进程、文件、地址空间以及进程间通信等逻辑概念。这种抽象虚拟机使得应用程序的开发变得相对容易：开发者只需与虚拟机中的各种逻辑对象交互，而不需要了解各种机器的具体细节。此外，这些抽象的逻辑对象使得操作系统能够很容易隔离并保护各个应用程序。 对于存储设备上的数据，操作系统向应用程序提供的逻辑概念就是"文件"。应用程序要存储或访问数据时，只需读或者写"文件"的一维地址空间即可

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I'm running a Linux 2.6.36 kernel, and I'm seeing some random errors. Things like ls: error while loading shared libraries: libpthread.so.0: cannot open shared object file: Error 23 Yes, my system can't consistently run an 'ls' command. :( I note several errors in my dmesg output: # dmesg | tail [2808967.543203] EXT4-fs (sda3): re-mounted. Opts: (null) [2837776.220605] xv[14450] general protection ip:7f20c20c6ac6 sp:7fff3641b368 error:0 in libpng14.so.14.4.0[7f20c20a9000+29000] [4931344.685302] EXT4-fs (md16): re-mounted. Opts: (null)

I have some :/test.sqlite3 database inside .qrc . And the goal is to directly use this database in program. Database used only for reading. QSqlDatabase::setDatabase(":/test.sqlite3") not works, because Qt SQLite not designed for working with Qt's filesystem. One of solutions is copying database from .qrc into D:\temdb.sqlite3 and using it by QSqlDatabase::setDatabase("D:\\temdb.sqlite3") . But program must not work with OS filesystem. Second solution is storing :/dump.sql in resources, then creating in-memory database by QSqlDatabase::setDatabase(":memory:") and importing dump into it by