Ploop mount/umount issue [message #50763] |
Mon, 28 October 2013 13:49 |
aw_idnt
Messages: 3 Registered: October 2013 Location: Hessen, Germany
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Junior Member |
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Hello there,
I have been playing around with OpenVZ and Ploop devices for quite a while now and right now I am stuck with a rather weird problem, which I like to share with you.
Any help is highly appreciated.
Environment:
OS: CentOS 6.4 x86_64
Kernel version: 2.6.32-042stab081.5 #1 SMP Mon Sep 30 16:52:24 MSK 2013 x86_64 x86_64 x86_64 GNU/Linux
Ploop-Version: ploop-1.9-1.x86_64
Testscenario:
1. Created Ploop-Image with the following command:
ploop init -s 8G -f expanded -t ext4 /storage/plooptest/test1/root.hdd
Creating delta /storage/plooptest/test1/root.hdd bs=2048 size=16777216 sectors v1
Adding snapshot {5fbaabe3-6958-40ff-92a7-860e329aab41}
Storing /storage/plooptest/test1/DiskDescriptor.xml
Opening delta /storage/plooptest/test1/root.hdd
Adding delta dev=/dev/ploop43259 img=/storage/plooptest/test1/root.hdd (rw)
Running: parted -s /dev/ploop43259 mklabel gpt mkpart primary 2048s 16775127s
Running: mkfs -t ext4 -j -b4096 -Elazy_itable_init,resize=4294967295 /dev/ploop43259p1
mke2fs 1.41.12 (17-May-2010)
Discarding device blocks: done
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
524288 inodes, 2096635 blocks
104831 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
64 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 26 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
Running: tune2fs -ouser_xattr,acl /dev/ploop43259p1
tune2fs 1.41.12 (17-May-2010)
Creating balloon file .balloon-c3a5ae3d-ce7f-43c4-a1ea-c61e2b4504e8
Mounting /dev/ploop43259p1 at /storage/plooptest/test1/root.hdd.mnt fstype=ext4 data=''
Unmounting device /dev/ploop43259
Works!
2. Mounted the newly created image with the following command:
mount -t ploop /storage/plooptest/test1/DiskDescriptor.xml /stroage/plooptest/mount/test1
Opening delta /storage/plooptest/test1/root.hdd
Adding delta dev=/dev/ploop43259 img=/storage/plooptest/test1/root.hdd (rw)
Mounting /dev/ploop43259p1 at /storage/plooptest/mount/test1 fstype=ext4 data='balloon_ino=12,'
Works!
3. Tried to unmount the device with the following command:
umount /storage/plooptest/mount/test1
Error in read_line (util.c:151): Can't open or read /sys/block/ploop43259p1/dev: No such file or directory
Unmounting device /dev/ploop43259p1
Error in ploop_stop (ploop.c:865): PLOOP_IOC_STOP: No such device
/usr/sbin/ploop umount -d /dev/ploop43259p1 command failed
Error in read_line (util.c:151): Can't open or read /sys/block/ploop43259p1/dev: No such file or directory
Unmounting device /dev/ploop43259p1
Error in ploop_stop (ploop.c:865): PLOOP_IOC_STOP: No such device
/usr/sbin/ploop umount -d /dev/ploop43259p1 command failed
The devie is still there in this scenario. I can read and write from/to it. However in another scenario yesterday the mountpoint was gone at the output of command "mount" but existed in /proc/mounts. The device was inaccesible (I got IO-Errors from it, when trying to access the directory). I will try to reproduce that and if possible post some data here later.
Any ideas?
Am I doing something wrong?
Is there a detailed documentation about ploop anywhere in the internet?
kind regards
Arne
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Re: Ploop mount/umount issue [message #50765 is a reply to message #50763] |
Tue, 29 October 2013 10:16 |
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curx
Messages: 739 Registered: February 2006 Location: Nürnberg, Germany
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Senior Member |
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please try use ploop util direct for unmounting, like
# ploop umount /storage/plooptest/test1/DiskDescriptor.xml -m /storage/plooptest/mount/test1
Is this ploop dev unmounted? (fixed a typo)
[Updated on: Tue, 29 October 2013 11:24] Report message to a moderator
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Re: Ploop mount/umount issue [message #50768 is a reply to message #50765] |
Tue, 29 October 2013 11:39 |
aw_idnt
Messages: 3 Registered: October 2013 Location: Hessen, Germany
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Junior Member |
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Well, this procedure is missing the obvious errors, but the result is still not entirely satisfying:
Ran the following command:
ploop umount /storage/plooptest/test1/DiskDescriptor.xml -m /storage/plooptest/mount/test1
Output:
Unmounting file system at /storage/plooptest/mount/test1
Unmounting device /dev/ploop43259
but:
/dev/cciss/c0d0p3 on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw)
/dev/cciss/c0d0p1 on /boot type ext4 (rw)
/dev/cciss/c0d1p1 on /storage type ext4 (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
/storage/plooptest/test1/DiskDescriptor.xml on /storage/plooptest/mount/test1 type ploop (rw)
while:
proc /proc proc rw,relatime 0 0
sysfs /sys sysfs rw,relatime 0 0
devtmpfs /dev devtmpfs rw,relatime,size=14326784k,nr_inodes=3581696,mode=755 0 0
devpts /dev/pts devpts rw,relatime,gid=5,mode=620,ptmxmode=000 0 0
tmpfs /dev/shm tmpfs rw,relatime 0 0
/dev/cciss/c0d0p3 / ext4 rw,relatime,barrier=1,data=ordered 0 0
devtmpfs /dev devtmpfs rw,relatime,size=14326784k,nr_inodes=3581696,mode=755 0 0
/proc/bus/usb /proc/bus/usb usbfs rw,relatime 0 0
/dev/cciss/c0d0p1 /boot ext4 rw,relatime,barrier=1,data=ordered 0 0
/dev/cciss/c0d1p1 /storage ext4 rw,relatime,barrier=1,data=ordered 0 0
none /proc/sys/fs/binfmt_misc binfmt_misc rw,relatime 0 0
sunrpc /var/lib/nfs/rpc_pipefs rpc_pipefs rw,relatime 0 0
As you can see "mount" still thinks, that the device is mounted, while it is actually unmounted.
Thank you for your help so far. I can work with this solution for now by ignoring /etc/mtab and /bin/mount respectively.
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