Bugzilla – Bug 133600
Can't find used/available space on usb drive - subfs
Last modified: 2005-11-15 17:59:44 UTC
When I plug a USB hard drive in, KDE identifies it as a USB Stick. A bit strange, but OK. But not fine is that I can't see how much space is used either from the KDE GUI or from the command line: bryce@linux:/media> df usb* Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda7 0 0 0 - /media/usbdisk /dev/sda3 0 0 0 - /media/usbdisk_1 /dev/sda5 0 0 0 - /media/usbdisk_2 /dev/sda6 0 0 0 - /media/usbdisk_3 /dev/sda2 0 0 0 - /media/usbdisk_4 /dev/sda1 23393 14 22171 1% /media/usbdisk_5 /dev/sda9 0 0 0 - /media/usbdisk_6 /dev/sda8 0 0 0 - /media/usbdisk_7 The blocks/used/available show up ONLY on the partition most recently written to. If I write to /media/usbdisk_6 then the blocks will go to zero on /media/usbdisk_5: Linux:/media # cd usbdisk_6 linux:/media/usbdisk_6 # echo > foo linux:/media/usbdisk_6 # cd .. linux:/media # df usbdisk* Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda7 0 0 0 - /media/usbdisk /dev/sda3 0 0 0 - /media/usbdisk_1 /dev/sda5 0 0 0 - /media/usbdisk_2 /dev/sda6 0 0 0 - /media/usbdisk_3 /dev/sda2 0 0 0 - /media/usbdisk_4 /dev/sda1 0 0 0 - /media/usbdisk_5 /dev/sda9 4623456 2930800 1457796 67% /media/usbdisk_6 /dev/sda8 0 0 0 - /media/usbdisk_7 Is SUSE mounting these in some strange way?
bryce@linux:/> df /dev/sda* Filesystem 1K-blocks Used Available Use% Mounted on - 257876 224 257652 1% /dev /dev/sda1 0 0 0 - /media/usbdisk_5 /dev/sda2 0 0 0 - /media/usbdisk_4 /dev/sda3 0 0 0 - /media/usbdisk_1 - 257876 224 257652 1% /dev /dev/sda5 9076744 78964 8536700 1% /media/usbdisk_2 /dev/sda6 0 0 0 - /media/usbdisk_3 /dev/sda7 0 0 0 - /media/usbdisk /dev/sda8 0 0 0 - /media/usbdisk_7 /dev/sda9 4623456 2930800 1457796 67% /media/usbdisk_6
This is full normal behavior. The devices are automatically mounted with subfs. If nobody access the partitions (e.g. for read/write) they are not directly mounted. They are only mounted for subfs. This mean they get mounted if you access them and only in this case. If you no longer access them they are automatically umounted by submountd. If you take a look at /proc/mounts you will see for the partitions you currently use/access two entries. One for subfs and one for the real mount. Because the not used partitions are umounted df can't know anything about them. They are deteced/named as usbstick, because you can't currently say if this is a harddisk or a usb-stick. Maybe a littlebit ugly buts not a bug.
Ok, I found instructions on disabling subfs: http://portal.suse.com/sdb/de/2004/05/hmeyer_91_revert_from_subfs.html http://portal.suse.com/sdb/en/2005/05/dkukawka_subfs_nomount.html But they are out of date for SUSE 10.0, and they don't completely remove subfs. Now I've had several troubles with subfs, how can I get rid of it?
If you wan't to disable subfs completly you must remove the submount package and you must do the mounts manually. No automount in this case. This is not supported by suse linux 10.0. Yes there are not up-to-date because the SDB should be merged in the wiki. We make updates after this merge.
Is there a way to hold the usb drive data into mind read from the last mount session? Clearly such data have to be cleared if the usb drive is unpluged.
I don't think so, but better ask a kernel guy (maybe Jeff or Chris)
Done
This must be the same reason that "Remove Safely" from KDE fails with "device is not in fstab"! Also: It sure would be nice if the "Remove Safely" menu from KDE worked, and also spun the disk down (e.g. hdparm -y /dev/xxxx or sdparm --command=stop /dev/sda or http://sourceforge.net/projects/noflushd/ or hdarm -S1 /dev/sda ). It simply does not feel safe to just unplug the drive!