I would like to simulate filesystem corruption for the purpose of testing how our embedded systems react to it and ultimately have them fail as gracefully as possible. We use different kinds of block device emulated flash storage for data which is modified often and unsuitable for storage in NAND/NOR. Since I have a pretty good idea of ...
I am writing a little application, which is writing jpeg images at a constant rate on a SD card. I choose an EXT3 filesystem, but the same behaviour was observed with an EXT2 filesystem. My writing loop looks like this : get_image() fwrite() fsync() Or like this : get_image() fopen() fwrite() fsync() fclose() I also display some ...
(Not really a programming question, sorry) I'm working on benchmarking various filesystems (most importantly: ext3) with various filesystem options (for instance: noatime, relatime etc.) for specific situations on a Linux box. For raw filesystem benchmarks, I'm looking into bonnie and bonnie++. What is the most useful way to use bonn...
We have a number of embedded systems requiring r/w access to the filesystem which resides on flash storage with block device emulation. Our oldest platform runs on compact flash and these systems have been in use for over 3 years without a single fsck being run during bootup and so far we have no failures attributed to the filesystem or ...
I know that NTFS supports encryption but otherwise is closed source. Likewise, I am aware of add-ins such as truecrypt but I am interested in encryption being built-in vs being bolted on. ...
An NTFS directory is open in a bash shell. what command will recursively truncate all filenames in a directory to the 255 character limit required for ext3? ...
Windows recognizes and gives my fedora partition a drive letter, but it shows it as blank. Is there a way to get windows to read ext3 filesystem? Its a fedora 10 partition. ...
We have several cron jobs that ftp proxy logs to a centralized server. These files can be rather large and take some time to transfer. Part of the requirement of this project is to provide a logging mechanism in which we log the success or failure of these transfers. This is simple enough. My question is, is there a way to check if a fi...
Hi all, Through a bit of digging, I've discovered how to set and get the volume name of an ext3 partition on my Linux box: set the volume label tune2fs -L MY-NEW-NAME /dev/disk/by-path/pci-0000\:00\:1f.2-scsi-2\:0\:0\:0-part1 get the volume's current level dumpe2fs -h /dev/disk/by-path/pci-0000\:00\:1f.2-scsi-2\:0\:0\:0-part1 | grep...
What's the easiest way to access an ext3 file system at the block level? I don't care for the files, or raw bytes, I just have to read the FS one block at a time. Is there a simple way to do this (in C)? Or maybe a simple app whose source I could look into for inspiration? I found no usable tutorials on the net, and I'm a bit scared to d...
Hi everyone. I wanna proramatically determine if a file has been modified since last time. I wonder if there is a flag or somthing like that on files under EXT3 filesystem. I'm writing a backup software. ...
I'm doing development of an OS based on the 2.4 Linux kernel. Right now I'm porting it to VMWare. When creating the partitions, either on first boot or when the user formats the drive (the user never formats the drive themselves, they use a special command in our OS that takes care of all the system calls for them), it gives the followin...
I have been seeing a few performance problems with a PHP script on a Linux Fedora Core 11 box, so I was running some commands to look for a bottleneck. One thing I noticed was that writing a file is pretty quick: [root@localhost ~]# dd if=/dev/zero of=/root/myGfile bs=1024K count=1000 1000+0 records in 1000+0 records out 1048576000 byte...
Curious as to the inode data structure differences between 128-byte ext2 and 256-byte ext3 file-systems. I have been using this reference for ext2, 128-byte inodes: http://www.nongnu.org/ext2-doc/ext2.html#INODE-TABLE. I have been unable to find a similar resource for ext3, 256-byte inodes. I have cursorily checked /usr/include/linux/...
I'm about to create a user based website and will have to store photo, docs and other data for each user. If I take a silly number like 1 000 000 000 users, I believe than one folder with 1 000 000 000 won't be the fastest thing in the world! So I was thinking of creating something like 1st level : [a-z] 2nd level : [a-z] 3rd level :...
I have a MySQL database that contains millions of rows per table and there are 9 tables in total. The database is fully populated, and all I am doing is reads i.e., there are no INSERTs or UPDATEs. Data is stored in MyISAM tables. Given this scenario, which linux file system would work best? Currently, I have xfs. But, I read somewhere ...
I am looking for a fast way to find the number of files in a directory on Linux. Any solution that takes linear time in the number of files in the directory is NOT acceptable (e.g. "ls | wc -l" and similar things) because it would take a prohibitively long amount of time (there are tens or maybe hundreds of millions of files in the dire...
Why are there no good drivers for Windows for reading ext2/3/4 filesystems? Googling around indicates that there's 2 or 3 out there, but all of them have problems. Is there some technical inconsistency that makes it difficult to correctly code up something that would enable me to open up My Computer and work with an extN partition just...
I have a 20-million record table in MySQL database. SELECT's work really fast because I have set up good indexes, but INSERT and UPDATE operation is getting to be really slow. The database is back-end of a web application under heavy load. INSERTs and UPDATEs are really slow because there are some 5 indexes on this table and index size i...
Hi Guys, I have a PHP application that for every request loads 1 ini file, and at least 10 PHP files. As these same files are loaded for every single request I thought about mounting them on a ram disk but I have been told that the linux filing system (ext3) will basically cache them in some way that a ram disk would not improve perfor...