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Bootable JFS vs. Bootable HPFS

Started by Terry, 2007.06.20, 16:20:18

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Terry

What are the PROs & CONs of the new eCS 2.0 Bootable JFS vs. the traditional Bootable HPFS?

This is from the eComStation 2.0 RC1 announcement:

"This release of eComStation contains the option to install the operating system on a JFS volume. The advantage of doing this is that the amount of diskcache is only limited by system memory (typically 10% of available memory is assigned) This increased cache size gives a huge gain in overall system performance. To install onto a Bootable JFS volume, you will have to select 'JFS' as filesystem type in the 'Format Volume' page of the installer."

Are there some legacy applications that may still require a bootable HPFS volume?



Glenn

It may be a personal judgment, but I would keep HPFS (I have an HPFS386 through an old WarpServer) on the boot drive, for a few reasons

- After a crash, I find it quite common that the OS boots up after a JFS checkup without correcting the errors. As eCS does not have the option that was implemented in Windows to unmount the file system before doing a chkdsk, you have to find a boot CD (or boot to command line using alt+f1,f2) to be able to do a full checkup (chkdsk /f:2) and clean-up the errors. With a JFS boot, the command line option does not work anymore, so you have to always have a boot CD next to you. This may be OK if you have a desktop PC, but not if you are traveling with a laptop.

- Depending on what you want to do with your PC, JFS will be fast or very slow. I noticed that JFS handles a directory with many small files very badly. For instance a PMMail mail directory will be read much slower on JFS than on HPFS. So I think that keeping both of the worlds is the best solution: HPFS(386) for the boot drive (with a few applications that may use small files, and with critical system files) and JFS for an applications drive.

I know this is a very partial view, but these will be my reasons to keep an HPFS boot drive.

abwillis

I have seen since JFS was first released that chkdsk sometimes just checks the log but doesn't fix problems if run due to a bad shutdown.  You can us the + in the config.sys in the autocheck part like below:
IFS=D:\OS2\JFS.IFS /LW:5,20,4 /AUTOCHECK:+*
in this case it will force a chkdsk on all JFS drives at boot.  One disadvantage, if you forget to remove the + then it will check the next boot too.

kim

Guess that this old article, OS/2 Filesystem Shootout, by Michal Necasek might be of interest.

warp

 ??? ::)
Boojfs partition to be out of sight in the (IBM) bootmanager ! This to look HPFS... Bug?
(kernel 14.093)

______
warp

melf

Just another personal view:
I've totally made a shift to JFS. Both my boot partition and my other partition. I find JFS overall very much faster, also at boot up. Initially there where some problems, but the last versions have worked without problems for me. That it doesn't correct errors at boot up I didn't know - on the other hand I have had no problems that I've noticed for a long time. eCS homepage have som article about JFS also:  http://www.ecomstation.com/ecomstation20.phtml?url=nls/en/content/bootablejfs.html&title=Bootable%20JFS

When one read other articles,PC journals, on different filesystems JFS2 (I guess this is?) have a lot of very good features in front of other systems, but I don't remember which.....
/Mikael

Blonde Guy

Quote from: Glenn on 2007.06.20, 17:21:47
For instance a PMMail mail directory will be read much slower on JFS than on HPFS.

I'm the project manager for PMMail, so I find this comment interesting. I tried opening PMMail Beta 2 on my test computer. (I can't do it on my main machine, because it doesn't have een one HPFS volume.)

Time to open PMMail with an one account with 29,000 messages (371 MB)
HPFS: 6 seconds
JFS: 1.5 seconds

To me, it looks like JFS is four times faster than HPFS.

Expert Consulting for OS/2 and eComStation

Terry

Quote from: Terry on 2007.06.20, 16:20:18

Are there some legacy applications that may still require a bootable HPFS volume?


It is not every day that you see a forum thread "bumped" and for a good comments at that...  So, I'll ask once again just to confirm one of the original questions...

Are there some OS/2 legacy applications that may still require a bootable HPFS volume?

This would seem to be a good reason to retain at a minimum, a bootable root HPFS partition, with JFS partitions following that first eComStation HPFS partition.

File reading speed, and greater file fragment stability are certainly reasons to go to JFS as per Melf's and Blond Guy's experience.

RobertM

Overall, it seems that on large writes, JFS beats HPFS & HPFS386 hands down - possibly due to the extra overhead of HPFS/386 trying to prevent fragmentation.

I've started playing with Ceres Sound Studio, and moved all my temp files to a JFS partition and the speed increase was phenomenal... yet other things seem to do better on HPFS386 (with the difference being that Ceres is usually writing or reading 50-300MB temp files from disk). This may partially be because Ceres (and other apps) dont report the file size when initiating a file write... when an app does report the file size, HPFS looks for an available block big enough and writes (usually) one solid file... without that file size, HPFS has a lot more overhead as it keeps looking for what it thinks might be an appropriate place to write the file or parts thereof (if I understand how HPFS works correctly). Because JFS does fragment and doesnt do all that fragmentation checking, it should be a lot faster for writing any file that it doesnt know the filesize for.

That makes JFS ideal for any file that will grow to an arbitrary file (log files, temp files, browser caches, etc), and HPFS better at not wasting space (smaller block size, and far less fragmentation).

My preferred solution is to have all my boot stuff on an HPFS(386) partition, and another one for the "lots of tiny files" directories, and then a JFS drive or 3 for the swap file, temp files, Mozilla, etc...

With my boot drive only containing what I need to boot (OS/2, any DLLs loaded at start, etc) HPFS' deficiencies in speed become irrelevant - and if need be, I can manually chkdsk the JFS partitions after boot (before I load anything located on them).

My next step is to install a 16GB Compact Flash Card on a CF to IDE connector, and transfer my temp and swap files to it... and see how that improves things.

-Robert


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Kirk's 5 Year Mission Continues at:
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warp

How it is necessary to use the undermentioned parameters, that from under Linux let him be visible the partition?
- add /G:gid /U:uid for compatible with Linux

_________
warp