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File creation time in EXT4

Most Linux administrators are aware of the three standard timestamps associated with a file, i.e. ctime, atime and mtime. What you may not be aware of is that many of the modern filesystems on Linux such as EXT4 and BTRFS also support a file creation timestamp. Here is what the stat command outputs on RHEL 6.4: # stat helloworld File: `helloworld’ Size: 6470 Blocks: 16 IO Block: 4096 regular file Device: 803h/2051d Inode: 396942 Links: 1 Access: (0775/-rwxrwxr-x) Uid: ( 500/ fpm) Gid: ( 500/ fpm) Access: 2014-05-14 06:30:45.107878096 -0700 Modify: 2014-05-14 06:30:36.337878203 -0700 Change: 2014-05-14 06:30:36.337878203 -0700 and here

EFI Stub "/etc/os-release missing"

When I updated my Fedora 20 installation today I ran into trouble booting my system using the EFI Stub mechanism even though it booted fine using GRUB. I ended up in the Emergency Shell. Looking at the logs using journalctl, here are the relevant entries (with times and irrelevant entries removed): [ ]: Reached target Switch Root. [ ]: Started Plymouth switch root service. [ ]: Starting Switch Root… [ ]: Not switching root: /sysroot does not seem to be an OS tree. /etc/os-release is missing. …. [ ]: Failed to start Switch Root. [ ]: Startup finished in 211ms

Some Ext4 Filesystems Cannot Be Converted to Btrfs

Not all ext4 filesystems can be converted to a btrfs filesystem using the btrfs-convert utility. Btrfs has some limitations. The mkfs.btrfs utility will complain if you try to create a fileystem that is less than 256Mb. Btrfs-convert used fail when a file had more than 244 hard links associated with it but that limitation is long gone. I hit another limitation recently when I tried to convert a 477Mb ext4 filesystem to btrfs. Btrfs-convert failed with a message of: block size is too small For some reason this Oracle document states that you cannot convert an ext4 /boot filesytem to