Experienced users and developers will no doubt already have the command line developer tools installed on their macOS machines.
There are three levels of journaling available in the Linux implementation of ext3: Journal lowest risk Both metadata and file contents are written to the journal before being committed to the main file system.
Because the journal is relatively continuous on disk, this can improve performance, if the journal has enough space. In other cases, performance gets worse, because the data must be written twice—once to the journal, and once to the main part of the filesystem.
This is the default on many Linux distributions. If there is a power outage or kernel panic while a file is being written or appended to, the journal will indicate that the new file or appended data has not been "committed", so it will be purged by the cleanup process.
Thus appends and new files have the same level of integrity protection as the "journaled" level. However, files being overwritten can be corrupted because the original version of the file is not stored. Thus it's possible to end up with a file in an intermediate state between new and old, without enough information to restore either one or the other the new data never made it to disk completely, and the old data is not stored anywhere.
Even worse, the intermediate state might intersperse old and new data, because the order of the write is left up to the disk's hardware.
The contents might be written before or after the journal is updated.
As a result, files modified right before a crash can become corrupted. For example, a file being appended to may be marked in the journal as being larger than it actually is, causing garbage at the end.
Older versions of files could also appear unexpectedly after a journal recovery. The lack of synchronization between data and journal is faster in many cases. JFS uses this level of journaling, but ensures that any "garbage" due to unwritten data is zeroed out on reboot.
XFS also uses this form of journaling. In all three modes, the internal structure of file system is assured to be consistent even after a crash. In any case, only the data content of files or directories which were being modified when the system crashed will be affected; the rest will be intact after recovery.
Functionality[ edit ] Because ext3 aims to be backward-compatible with the earlier ext2, many of the on-disk structures are similar to those of ext2. Consequently, ext3 lacks recent features, such as extentsdynamic allocation of inodesand block sub-allocation.
Where filesystem metadata is changing, and fsck applies changes in an attempt to bring the "inconsistent" metadata into a "consistent" state, the attempt to "fix" the inconsistencies will corrupt the filesystem.
Defragmentation[ edit ] There is no online ext3 defragmentation tool that works on the filesystem level. There is an offline ext2 defragmenter, e2defrag, but it requires that the ext3 filesystem be converted back to ext2 first.
However, e2defrag may destroy data, depending on the feature bits turned on in the filesystem; it does not know how to handle many of the newer ext3 features. If there are files which are used at the same time, Shake will try to write them next to one another.
Defrag works by copying each file over itself. However, this strategy works only if the file system has enough free space. A true defragmentation tool does not exist for ext3.
Some filesystems, like ext3, effectively allocate the free block that is nearest to other blocks in a file. Therefore it is not necessary to worry about fragmentation in a Linux system.
Undelete[ edit ] ext3 does not support the recovery of deleted files. The ext3 driver actively deletes files by wiping file inodes  for crash safety reasons. There are still several techniques  and some free  and proprietary  software for recovery of deleted or lost files using file system journal analysis; however, they do not guarantee any specific file recovery.
Compression[ edit ] e3compr  is an unofficial patch for ext3 that does transparent compression. It is a direct port of e2compr and still needs further development.
It compiles and boots well with upstream kernels[ citation needed ], but journaling is not implemented yet. Lack of snapshots support[ edit ] Unlike a number of modern file systems, ext3 does not have native support for snapshotsthe ability to quickly capture the state of the filesystem at arbitrary times.It's even more, i heared from others that they ask for a mid range 5 digit number.
You have to send your business plan and then they come up with a price that leaves you with just enough profits to buy a bowl of rice for your hungry programmers. fuse-ext2 works but is very slow (I get some 7 MB/s reading and 1 MB/s writing via USB ). If you have the choice, better use Apple's HFS+ on the external drive, which is much faster (I get some 30 MB/s both reading and writing, both on Mac and Linux).
FUSE has its limitations, however. File system access performs less well than with native kernel support, for example. On the other hand it offers vast flexibility in storage options. Mar 26, · Thanks for Fuse-ext2, it's wonderful! dvodvo Posted 01/03/ fuse-ext2 works but is very slow (I get some 7 MB/s reading and 1 MB/s writing via USB )/5(10).
Fuse-ext2 is a multi OS FUSE module to mount ext2, ext3 and ext4 file system devices and/or images with read write support. How do I mount ext2/ext3 partitions in Mac OS X Snow Leopard?
Ask Question. fuse-ext2 works but is very slow (I get some 7 MB/s reading and 1 MB/s writing via USB ).
To get write access even to a journaled partition on Ubuntu, install support via sudo apt-get install hfsprogs and when the drive is mounted (e.g.