When using an ext4 filesystem for MythTV, here are a few tricks to help improve speed.
First of all, always create a separate partition for your recordings! Here’s how to ensure that it is optimal.
Let’s say that you create a partition on device /dev/sdb.
- mkfs.ext4 -T largefile /dev/sdb1
- tune2fs /dev/sdb1 -o journal_data_writeback
- echo “/sbin/blockdev –setra 4096 /dev/sdb” >> /etc/rc.local
In the first step, we tell ext4 to format tuned to use large files. This reduces the number of inodes, maximizing the available space and (unconfirmed, but hypothesized) minimizing the journal size.
In the second step, we enable writeback mode for the filesystem as a default mount option. This is normally not a safe step, but we are only protecting TV content that is already very robust at working in the face of errors. Setting this option allows the OS to write to the disks without 100% lock-step synchronicity.
Now add these options to /etc/fstab.
This option in the fstab tells the OS not to change the last accessed times on the files and folders every time a file is accessed. This reduces unnecessary writes, which improves overall performance.
Your fstab might look something like this:
UUID=2a59a579-9779-455c-bfed-d7e69c5ec533 /shared/recordings ext4 defaults,nodiratime,noatime 0 0
That’s it! Happy watching.