I'm trying to exhange files with a linux (redhat 7.2) user.
The idea is to ship a 500GB LaCie d2 "big disk" back and forth.
I sent him the disk formatted Macosx UFS. Unfortunately he aparently can't read the disk (Redhat 7.2). I think we can
work around this (I hope). What i sent is only 30GB and we think he'll be able to move the files around somehow at his end. But then he has to send me back around 250gb of data (lots of 25Mb or less files if that makes any difference).
My qustion is, if I install extfsx on my mac (imac 17" flat screen, os 10.34) is there a pretty good chance I'll be able to read
chance that I will be able to read
the disk if he formats on his linux machine as an ext2/3?
Well, I would generally say there would be no problems, but there is a recent thread on this list that claims there are issues with large drives ("kernel panic with iomega hdd 250 ext3"). From his description though it may actually be a problem with any drive that is 60% or more full. I have yet to to test this out, but keep it in mind and take a look at that other thread.
FWIW, I've copied the entire Apple Developer directory w/o problem and that is about 20K files @ 1GB. I've also tested individual files up to 4.5GB w/o problem.
Well, we are going to give it a try. Looks like he
has about 300gb of data to put on the disk so it
will be about 60% full. Hope this works. I'll let you know.
To test the 60% theory, I created a 256MB ext2 disk image.
Then filled it up. No problem.
Of course this was a disk image, not a real disk,
and a small one at that.
Well, that's very cool. Thanks for that. Maybe it is just large disks then. Let me know if you have any problems.
Well my partner in this effort started to write my disk.
Unfortunately the only way he can connect this disk
to his linux system is via usb1. At that rate we estimate
it will take 4-5 days to write the data. (good thing
he was not using this disk to do the work!)
This gives me lots of time to decide if I'll need to
make a linux box to read the disk, and to build
the box if needed. I also decided I wanted to be
able to back up the data locally. So I bought another
500gb disk to experiment with while I'm waiting.
I formatted the new disk as ext2 using ext2fsx.
Last night I wrote about 260gb of data to the disk.
This morning I wrote some more data - no problems.
Then I used the extFSmanager pref pane to enable
indexed directories. remounted the disk. Copied
another 40gb of data to the disk. BTW, it seems
enabling indexed directories can not be undone
(at least not by the pref pane). It might be my
imagination (I didn't time things) but it seems that
enabling indexed directories slows down writes
a little bit. Then I enabled ignoring permissions.
remounted the disk again. and am currently
writing another 40gb of data to the disk.
BTW, it is not clear to me the difference between
unmounting a disk and ejecting it. The extpref pane
only allows me to unmount it. Disk Utility gives
me the option to do either. Using the finder controls
I guess ejects it. It appears they are functionally
equivalent and result in a clean filesystem.
So anyway, so far I have written about 325gb of
data to the disk. read and writes are working fine.
Unmounting and remounting the disk seems to
be working fine. I am getting more confident that
this is going to work. As long as the ext2 file
system created by his linux box (running one of
the fudora versions of redhat) is the same as
the one created by ext2fsx I should be good to go.
It doesn't appear that ext2fsx has a generic problem
with large file systems. I don't think I'll bother building
myself a linux box for home.
If you have any more tests you'd like me to run
on this big disk, just let me know. Once my other
disk is in the mail I'm going to reformat this one
as an HFS+ volume. Probably next week sometime.
This is going to be a pretty long posting, sorry, but,
I hope it will be useful to somebody. There will actually be a question at the end.
So, I got my big disk back today.
Plug it in, and the finder tells me:
"You have inserted a disk containing no volumes that Mac OSX can read.
To continue with the disk inserted, click Ignore."
So I click ignore.
I try using the EXTfsmanager preference pane to mount the disk and get
This suggests, that maybe the file system is bad, so, I run fsck on it.
david% sudo fsck_ext2 -f /dev/disk2s3
e2fsck 1.35 (28-Feb-2004)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
Graham: 47368/61063168 files (14.6% non-contiguous), 112403599/122097106 blocks
Yes, the disk is VERY (too) full! But at least it showed no errors.
Then try to mount it manually.
mount_ext2 /dev/disk2s3 mnt
And I can see the files on the disk in mnt from the command line. Yea!
Now try to get the finder to see it:
Nope, disk does not show up in the finder. Unfortunately the application
I want to use to process this data apparently can't see the disk unless the finder sees it.
So, lets try the ExtFSManager pref pane again. No good, it
gives me the Error: 0x1FFFFFFF still.
So I read the ReadMe again and find:
" If you re-format an existing partition as Ext2, then that partition may fail to automount in the future. This is because re-formating does not change the partition type in the partition header of the disk."
Ouch, I'll bet this is my problem.
Using plist I find:
/dev/rdisk2 map block size=512
#: type name length base ( size )
1: Apple_partition_map Apple 63 @ 1
2: Apple_Boot eXternal booter 17408 @ 64 ( 8.5M)
3: Apple_UFS Apple_UFS_Untitled_2 976776848 @ 17472 (465.8G)
4: Apple_Free 0+@ 976794320
Sure enough. When I sent him the disk it was formatted as one
large apple UFS file system (which he could read from his linux box, but not
write to). He must have newfs'ed the disk, but not repartitioned it. Haven't
been able to contact him to confirm this yet. I'm not brave enough to try
using pdisk to relabel the partition as ext2, at least not until I have the data off it
Guess I'll run rsync -rul on it tonight to a volume the finder can mount.
Bottom line is I think this is going to work, I started rsync'ing the ext2 volume to an HFS+
volume and can read the files in the finder from the HFS disk. I'll find out probably tommorow if it actually copied all the files properly
Let this be a warning to other users of this fine software - if you want the finder to be able to see the disk make sure you partition it as an ext2 volume.
Does my analysis that the finder can't see this disk because it is an ext2 filesystem
on a disk partition that my mac still things is ufs sound correct?
Thanks, I owe you a (virtual) beer, or something
No need to worry. Mount the partition manually as you've been doing. While the Finder won't see it as a mounted partition, it will see it as a "Folder".
Outside of the fact that you'll have to deal with mount/unmount, it is a fully functional mountpoint at the unix level. The finder just doesn't know it's a different drive. You can probably survive that ;)
I think you hit the nail on the head. This is a limitation of the system disk manager. Like I said in the ReadMe, the hint is actually literal.
Not much you can do other than reset the type as Ext2 using pdisk, or re-format the whole drive.
Actually, I'm not sure that this is the problem. I stumbled on this thread having the _exact same problem_, down to the LaCie BigDisk and everything. The drive was actually partitioned and formatted under a Linux box, so I would imagine that it had the proper information.
Like the parent, I managed to mount the drive to a folder and proceed as normal (copy all of the data off onto a drive that OSX natively recognized), but couldn't get it recognized at all using any of the GUI tools.
Interestingly, while the drive was attached via firewire and mounted, I wasn't able to get any other firewire drive to be recognized either. To add another drive to copy to, I had to first umount the ext2/3 drive, plug in the HFS drive, have it be automounted, then remount the ext2/3 drive.
I got the data off, but figured someone else might be interested if they had the same problem. For information, I was using a 500GB LaCie BigDisk with 224 GB filled on a dual 2GHz G5, OSX 10.3.2, extfsx v1.2.
No worries. I got the data off the disk, then reformated it.
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