PFS vs SFS vs FFS - Best Filesystem
 

I haven't kept up with anything Amiga for a while so I'm trying to play catch-up. Right now, filesystems.

For a HDD, I'm going to assume FFS isn't even worth considering anymore, correct?

The last Aminet upload for SFS was 2007 so I'm guessing that's out of the running.

I've seen Toni doing a lot for PFS, and given his track record, I assume it's the best filesystem these days, especially since it runs on any Kickstart and on 68000+.

Correct? Anything else worth noting?

FFS is still the best regaring data safety and recoverability.

PFS is the best regarding speed and continuousness.

SFS is somewhere in between.

The biggest disadvantage of PFS is that it concentrates all meta data in the beginning of a partition. If that area of the partition gets damaged, everything is lost. Even though more than 70% of the partition might still be intact, you cannot recover anything because you don't know what to do with the data.

SFS has a similar problem. It does not have a similar single point of failure as PFS, but if the right portion of the partition is damaged, you cannot get your data back. There is only one recovery program for SFS and it does not work. At least I never got it to even start.

And what are the recovery options for modern FFS? I would not dare to let old QuarterBacktools (or worse, DiskSalv) loose on FFS 45.16 or whatever is current (what is current?) :)

I think the major feature for PFS3AIO is that it is actively developed.

I guess it's FFS for me, because I think this is a big deal.

Fingers crossed that Toni eventually implements this functionality into PFS!

Olaf Barthel is working on an updated DiskDoctor that supports all FFS variants, and actually works, unlike its older counterpart. He said it is a complete rewrite. He already posted a little bit of information about that on Amiga.org and Thomas Richter also confirmed that too.

FFS is the best for the system partition, or for partitions on which you need to write often and are at risk of damaging. I wouldn't use FFS 45.x, though - I value DiskSalv too much.
Just keep it under 4GB and you're safe.

SFS is good when you have extra-large files that need seeking (FFS sucks on this) but don't write too often so risk of damaging is small. Sometimes its ".recycled" hidden dir saved me from big burden.

PFS, i don't know. It ate some data of mine years ago and i don't forgive these things easily, even if it was an old version.

Still considering writing my own filesystem. Even have some specs somewhere but it never got to code.

The opposite is true. The boot partition gains most from SFS or PFS. With PFS the boot process feels like three times faster than with FFS, especially on slow machines.

And of course the boot partition is the one which can easily be recreated from scratch. It only holds files which were delivered on install media. The other partitions usually contain your creative work which is much more valuable.

PFS has the .deldir which does the same.


For me it was the other way round: SFS ate a whole partition. PFS has its disk structure openly documented, even in the commercial version, so in the worst case you could write your own recovery software (which I did). SFS is closed, undocumented and unsupported.

No.

PFS also destroyed some of my data so I switched to SFS. It always worked reliably for me so I never changed to something else.

To be fair, I don't trust _any_ Amiga filesystem, especially not with modern large devices where errors and bit flips are statistically unavoidable. The main reason for having a network stack on Amiga is to move "important data" away from them as soon as possible :)

Never felt the boot process was sluggish, quite the opposite. But ok, i don't install lots of garbage.
Anyway, i didn't want a separate partition for system and my own files so no, it can't be recreated from scratch in my case.


From these experiences, FFS seems to be the most reliable...

FFS is similar to FAT, it has lots of redundancy, uses old and inefficient data structures, which makes it practically impossible to completely break but it also does not scale to bigger drive/file sizes, for example large file Seek() times are painfully slow.

Same or me. SFS failed twice (some error kept appearing all the time, at least data was intact) and that so called recovery program has never worked. Drive was ~400M or so (20+ years ago), it surely was not caused by 4G limit or anything else.

ok my experience :

- FFS is just too slow.

- SFS failed and bitched on me 3 times.

- PFS3 AIO seems to be the best in term of reliability and speed.

PS : never ever use tools like Quarterback on any partition using SFS or PFS. It will corrupt straight the formatting.

I have had small/medium problems with FFS (OS3.1), PFS3 and SFS over the years starting from 1996 with 1,2GB HD (with FFS) to now 80GB HD. I do backups on a second HD in my A1200 since 1998/99 (switch to PFS3 because I wasn't satisfied with FFS). Some years later with a new larger HD PFS3 failed when format = crash. So I tried SFS what worked with that HD. Since then I use SFS. PFSDoctor and SFSSalv worked both and were needed some time. SFSSalv has some bugs and needs a lot of memory. The larger the partition the larger the amount of memory used. So it might fail. .recycled and .deldir are both great but can also make problems. I remember got in trouble with .deldir and many large files. Don't use it on partition that contain only temp/unimportant data (can speed up a lot). On SFS partition with problems/errors I would recommend to make an backup, quick format and restore data.

If you use FFS, SFS or PFS you can't trust the filesystem or the hardware itself. Problems can occur by filesystem, other software, hardware failure, over voltage or something else. So have at least one backup.

Developer information for SFS is/was available. Developer.txt says so.

Very true.
My gaming setup consists of an 8GB CF with 4 partitions:
* Boot partition: PFS3AIO
* 3 data partitions with games, demos and music: FFS, locked to be read-only

Why read-only? The biggest damn pain on FFS is accidental reset while accessing the drive causing those damn validation errors and lengthy validation processes... If you lock it, you can't ruin it. This way the system is very stable and the PFS3AIO boot partition boots really fast on my "slow" system.
Unlike what is said above, I always found that it's too easy to shove a drive into the validation process. An HD-installed game that crashes can do it.
If you need to write to any of those partitions it's as easy as typing a shell command so there's no loss.

I never had a problem with PFS3 until recently when a well-documented bug ate all of my data in one partition. That bug has since been squashed.
FFS has always seemed to me as very unreliable and quite slow on when you have lots of files, but for my use and the way I have it set up, it works just fine.

SFS can be your choice due to your anecdotal experience, but has shown its deficiencies over time, which have never been addressed as there is no support for it whatsoever, and remains without proper recovery tools.

On the contrary both PFS3 and FFS are still supported and have proper recovery tools. PFS3 is open source and FFS has been documented extensively, so much that there is support for it even under Linux.

With the upcoming AmigaOS 3.1.x one of the features as mentioned in the press release, is a fast file system with native 64-bit support for NSD, TD64 and direct SCSI, long file names and resizable media support and... bug fixes.

So choosing SFS over PFS3 or FFS is just a bad idea, but of course, you are always free to do what you want. :)

If you want redundancy, try OFS. If you want unvalidated partitions, try FFS. If you want the slow delete issue, do SFS (curses that I formatted my MOS system with it).

If you want Toni to loose hair with incomplete bug reports, do PFS.

As soon as I heard about AFS (AmiFileSafe), ~1990?, I bought it and left with no regret the FFS (FastFileSystem). Even if my HD was only about 500MB at that time, to my experience FFS was just fast as in-validating partitions and loosing data.
Nevertheless I have to admit that this is thanks to these problems that, at that time, I was mastering archiving tools like lha :great . So retrospectively, FFS had that good point for me.
With AFS, I encountered some issues but much lesser than with FFS. So I was really happy. Then it's naturally that I moved to PFS*, PFS2, PFS3 and now PFS3aio (thank you Toni). With PFS, I do not recall any issues (except once or twice when I turned of the computer during some writing - so not the FS fault :D )
I can't remember if I did try SFS, maybe I did, like muFS but not enough to mention here ;) .

* Edit: Memory mistake :p . According to the FAQ of PFS3, PFS (public domain) was released before AFS (commercial product). Then PFS2 (commercial product) succeeded to AFS and PFS3 (commercial product) succeeded to PFS2.
This is also interesting regarding SFS.

I used SFS for a long while, while PFS3 was still commercial.
The main problem with SFS was, back then, that it didn't run on anything lower than an 020. So 68000 machines were immediately discarded from the equation.

That is another factor when weighing in SFS, if you have a 000 machine, it's not an option.

So I never tested SFS for sure now ! ;)