Fwd: file systems

---------- Forwarded message ----------
From: Heddle Weaver <weaver2world@gmail.com>
Date: 21 April 2011 22:13
Subject: Re: file systems
To: Stan Hoeppner <stan@hardwarefreak.com>

On 20 April 2011 19:57, Stan Hoeppner <stan@hardwarefreak.com> wrote:

Heddle Weaver put forth on 4/19/2011 6:58 PM:

> XFS is excellent for large file sizes - graphics, music, videos, etc, but
> ext3/4 are better for a range of file sizes and therefore better for a

This is simply not true. Modern XFS is just as performant with small
files as EXT3/4, especially with multiuser or highly parallel workloads.
EXTx traditionally has had two advantages over XFS:

1. Workloads with zero or low parallelism
2. Metadata write heavy operations

The first typically holds true for many single threaded workloads.
That's fine. XFS was designed for single threaded workloads, but high
bandwidth multithreaded workloads.

The second evaporated when Dave Chinner introduced delayed logging last
year. Today XFS metadata operations are on par with all Linux
filesystems, and surpass all others with many workloads.

Apparently you've not used XFS for maildir storage. It's throughput is
quite a bit better than EXT3/4. Based on the file types you mention
above, it would appear you are strictly a desktop Linux user. This
would explain your lack of knowledge of XFS and your penchant for
repeating misinformation. It would also explain and your preference for
EXTx.

> smaller operation, which is what the O.P. seems to be describing.

XFS is just as applicable to a small operation as a large one. For
instance, it is the premier filesystem used in building MythTV servers.
A DVR is a pretty small operation. XFS is the only Linux filesystem
with a defrag utility, and an online one at that. This is beneficial to
all operations, regardless of size. XFS has a far richer set of
management tools than any other Linux filesystem.

You simply can't go wrong with XFS on any size server, assuming you
first read the basic documentation and the XFS FAQ.

> In case of
> mishap, they fall back to ext2.

I'm not sure exactly what you mean by this. I doubt you are either.

http://tinyurl.com/3tu3ww9

And this example is somewhat dated, but illustrates one such instance:

http://tinyurl.com/3qjtj82

What kind of "mishap" would require converting the EXT3/4 filesystem
back to EXT2?

> Performance is trivial, as any file system can be tuned.

This statement clearly demonstrates your lack of filesystem architecture
knowledge.

I've done it a number of times. No lack of knowledge in this regard at all. You might have to reassess this one as well.

Just as you can't tune a Ford Pinto to outrun a Ferrari, you
can't tune EXTx to outperform XFS in highly parallel workloads.

That particular parallel simply doesn't work. Cars?

Your religious fervor does you credit, but beware of crucifixion. Yours and others.
Regards,

Weaver.

Religion is regarded by the common people as true, 
by the wise as false, 
and by the rulers as useful. 

— Lucius Annæus Seneca.

Terrorism, the new religion.