[mythtv-users] Dropped frames, simultaneous recordings and process priorities.

[Gary Buhrmaster]

On Mon, May 13, 2013 at 2:27 PM, Joseph Fry <joe at thefrys.com> wrote:
>
>> Also, it is very important to use JFS or XFS for recording partitions,
>> as deleting huge video files from EXT partitions frequently causes so
>> much activity that it will prevent recordings from working.
>
>
> This is not true for EXT4.  EXT2 & 3 will be slower for large file deletes
> in most cases;

Ext4 is faster because it uses extent based allocation schemes.
This has numerous benefits, including fast deletes (and reduced
fragmentation).  JFS, XFS, btrfs, VFS and others also use extents
(note that you do not need to use an extent based allocation
scheme to achieve "fast deletes").

> however I seem to recall that on advanced format drives (4k
> sectors), you can expect deletes to be about 4x-8x faster than the same file
> size on a 512byte sector drive.

Most modern file systems can use block allocation sizes in a multiple
of the underlying sector size.  (Allocation size is sometimes called
cluster size.)  Even with 512B sectors, many modern file systems use
4KB (or greater) as the logical block size for modern hard drives.  So,
whether the disk uses 4KB sectors or not tends to be less relevant,
as the file system is already using the logical block size.

Gary