JFS on removable drives

Apart from handling gigantic volumes, which I don't need, there seem to be
two big advantages in JFS. And I seem to be getting these advantages on a 
fixed disk, but not on removable.

(Here I'll use Removable and USB as synonyms; if there are exceptions, I'd
be interested.)

1. After a bad system shut-down, a JFS volume is quickly recovered using 
the journal, which is a huge advantage when there are gigabytes. (How fast
is it if anything is actually wrong? I haven't yet seen that.)  

But on my USB disk this doesn't happen, at least when the drive is 
hot-mounted while the system is running.  The volume comes up unreadable, 
just like a plain HPFS, and seems to take as long in CHKDSK as hpfs does; 
the little phase messages are more fun to watch, but that doesn't really 
help.


2. You can add pieces to the volume at any time from free space or blank 
partitions.  It works, to all appearances, on the fixed drive.  

But LVM will not offer me the option to expand a JFS volume on the USB 
drive. This would be almost logical if the designers were afraid of 
extending a volume onto a drive that might not be there next time.  But 
LVM offers to extend my fixed-disk jfs volume onto a partition on 
removable disk! (I haven't tried that, and don't plan to.) It just won't 
extend the volumes on usb drive at all.


Is this the way it's supposed to work?

BTW: ecs 1.0 fully updated; SCSI fixed drivis; just started using jfs last
week.


-- 
Dan Drake
dd@dandrake.com
http://www.dandrake.com/

First of all, if you want use JFS on flash disks, it's necessary use 
JFS.IFS for eComStation. It contains important fixes for this task.
 

On Sat, 20 May 2006 11:38:38 UTC, eugenegorbunoff@mail.ruDESPAM (Eugene 
Gorbunoff) wrote:

> First of all, if you want use JFS on flash disks, it's necessary use 
> JFS.IFS for eComStation. It contains important fixes for this task.

Any preferred version or date? Naturally I've been using an ecs JFS driver
on my ecs system, but it wasn't new. Now I've fetched jfs.ifs from a 1.2MR
system; also the one that's on the ecs website, version 14100 with the 
date 2004-08-19 (in a much newer zip file). Neither will expand a new JFS 
volume on a usb disk; any of them will expand a jfs volume that's on fixed
disk even _onto_ a usb disk.

Can anyone tell me if JFS is *supposed* to work the same on removables as 
on fixed disk? Does anyone *have* it working that way? Does it make a 
difference if it's on a USB disk (real disk) rather than some other 
removable device? Does it make a difference if the disk's grandfather is 
named Trespassers William?




-- 
Dan Drake
dd@dandrake.com
http://www.dandrake.com/