#4995 Active Swap/Virtual Memory partition incorrectly shows as not in use

[Aria Bamdad]

Hi,

I am using webmin 1.850 on SUSE SLES 12 SP2, running on IBM z System (s390x) architecture hardware. When you go to System -> Disk and Network (or Filesystems), the disk partitions listed as 'virtual memory' for swap space are labled with 'No' under the 'In Use' column. This problem is not limited to Webmin 1.85. I see the same in previous releases. I also see the same problem for SUSE SLES 11.

The particular swap disks in my case are defined as special 'VDISK' in the hypervisor z/VM. These disks are virtual disk in memory. I have not tested to see if webmin behaves the same with physical disks. Regardless, the response should not be 'No' for In Use.

Here is the output for swapon -s command:
Filename Type Size Used Priority
/dev/dasdb1 partition 64980 0 100
/dev/dasdc1 partition 64980 0 -1

Here are the definitions in fstab:
/dev/disk/by-path/ccw-0.0.0155-part1 swap swap pri=100 0 0
/dev/disk/by-path/ccw-0.0.0156-part1 swap swap defaults 0 0

Here is the output on the Disk and Network Filesystems screen:
Virtual Memory Virtual Memory (swap) /dev/disk/by-path/ccw-0.0.0155-part1 No Yes
Virtual Memory Virtual Memory (swap) /dev/disk/by-path/ccw-0.0.0156-part1 No Yes

Please let me know if you need additional information.
Thanks,
Aria

[Jamie Cameron]

Can you post the contents of /proc/swaps on this system?

[Aria Bamdad]

/proc/swaps contains:

Filename Type Size Used Priority
/dev/dasdc1 partition 64980 0 -1
/dev/dasdb1 partition 64980 2176 100

test:~ # l /dev/dasdc1
brw-rw---- 1 root disk 94, 9 Jul 12 17:40 /dev/dasdc1
test:~ # l /dev/disk/by-path/ccw-0.0.015*
lrwxrwxrwx 1 root root 11 Jul 12 17:40 /dev/disk/by-path/ccw-0.0.0150 -> ../../dasda
lrwxrwxrwx 1 root root 12 Jul 12 17:40 /dev/disk/by-path/ccw-0.0.0150-part1 -> ../../dasda1
lrwxrwxrwx 1 root root 11 Jul 12 17:40 /dev/disk/by-path/ccw-0.0.0151 -> ../../dasdd
lrwxrwxrwx 1 root root 12 Jul 12 17:40 /dev/disk/by-path/ccw-0.0.0151-part1 -> ../../dasdd1
lrwxrwxrwx 1 root root 11 Jul 12 17:40 /dev/disk/by-path/ccw-0.0.0152 -> ../../dasde
lrwxrwxrwx 1 root root 12 Jul 12 17:40 /dev/disk/by-path/ccw-0.0.0152-part1 -> ../../dasde1
lrwxrwxrwx 1 root root 11 Jul 12 17:40 /dev/disk/by-path/ccw-0.0.0155 -> ../../dasdb
lrwxrwxrwx 1 root root 12 Jul 12 17:40 /dev/disk/by-path/ccw-0.0.0155-part1 -> ../../dasdb1
lrwxrwxrwx 1 root root 11 Jul 12 17:40 /dev/disk/by-path/ccw-0.0.0156 -> ../../dasdc
lrwxrwxrwx 1 root root 12 Jul 12 17:40 /dev/disk/by-path/ccw-0.0.0156-part1 -> ../../dasdc1

[Jamie Cameron]

Ok, that's an unusual device name. Is the same /dev/dasdb1 device used in /etc/fstab ?

[Aria Bamdad]

The device name 'dasd' is normal for IBM System z environment. It is equivalent to sd and hd and points to a diskdevice. However normally you don't want to use the by name devices such as dasda, dasdb because the order the device comes online at boot may change. Therefore, it is preferred to use the 'by-path' name as in /dev/disk/by-path/ccw-0.0.0152-part1 meaning device at address 152.

I had posted my fstab originally:

Here are the definitions in fstab:
/dev/disk/by-path/ccw-0.0.0155-part1 swap swap pri=100 0 0
/dev/disk/by-path/ccw-0.0.0156-part1 swap swap defaults 0 0

Thanks.

[Jamie Cameron]

Ok, I see the cause of this bug now - it will be fixed in the next Webmin release.

[Aria Bamdad]

Thank you.