Categories
Linux Mastering Development

qemu: uncaught target signal 11 (Segmentation fault) – core dumped

I have problems with chroot. I have a host machine which is amd64 and I want to work using qemu on aarch64 and I tried using this script: #!/bin/bash echo ">>>" echo ">>> Configuring ARMv7-A environment" echo ">>>" echo $PWD echo ‘:arm:M::\x7fELF\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/local/bin/qemu-arm:’ > /proc/sys/fs/binfmt_misc/register echo ">>> mounting filesystems" mount -t proc proc $PWD/proc || echo […]

Categories
Linux Mastering Development

Systemd Journal fails to open /run/log/journal file

I was playing with BPF tools today and ran the command sudo opensnoop-bpfcc -x -U and noticed many traces like this: 0 403 systemd-journal -1 2 /run/log/journal/5c01742aed6d4d58bed5f1671e612657/system.journal … and then I ran: $ ls -al /run/log/journal/ total 0 drwxr-sr-x+ 2 root systemd-journal 40 Jun 28 15:06 . drwxr-xr-x 3 root root 60 Jun 28 15:06 […]

Categories
Linux Mastering Development Ubuntu

Is the `size` parameter for tmpfs in fstab not working?

I am confused about whether my /tmp using tmpfs is respecting the size parameter that I gave to it in /etc/fstab: My fstab entries now read: root_pool/var/tmp /tmp /var/tmp zfs rw,nodev,nosuid 0 0 tmpfs /tmp tmpfs rw,nodev,nosuid,noexec,nr_inodes=5k,size=2G,mode=1777 0 0 tmpfs /dev/shm tmpfs defaults,nodev,nosuid,nr_inodes=5k,mode=700,size=4G 0 0 But according to du, it is using half of my […]

Categories
Linux Mastering Development

Apache failed to start with PrivateTmp=true after I changed the /tmp folder

Apache service cannot start and I know the reason but not sure how to fix it: Apache error: apache2.service – The Apache HTTP Server Loaded: loaded (/lib/systemd/system/apache2.service; enabled; vendor preset: enabled) Drop-In: /lib/systemd/system/apache2.service.d └─apache2-systemd.conf Active: failed (Result: exit-code) since Tue 2020-06-02 15:32:34 UTC; 3s ago Process: 1918 ExecStop=/usr/sbin/apachectl stop (code=exited, status=226/NAMESPACE) Process: 2028 ExecStart=/usr/sbin/apachectl start […]

Categories
Linux Mastering Development

mount same tmpfs on two mountpoints

I have this in my /etc/fstab: tmpfs /home/user1/tmp tmpfs rw,nodev,nosuid,noexec,size=16G 0 0 user1 has tmpfs mounted as /home/user1/tmp. I would like to mount same tmpfs for user2 as well, so that they can share same tmpfs. How can I do this in fstab, so that user2 has same tmpfs mounted at /home/user1/tmp ?

Categories
Mastering Development System & Network

slow read on openzfs/Linux via NFSv3 on Debian 10

because of my unanswered question : qemu snapshot exclude device i decided to use NFSv3 for the VM to handle user data. Because of slow performance of BTRFS after maintance-tasks i use now zfs Raid1 Version: buster-backports 0.8.3-1 on the Debian Host. BUT: the performance via NFS is exorbitant slow; first for both write and […]

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Linux Mastering Development

Ubuntu 20.04 and sudo privileges [duplicate]

I just upgraded to a brand new fresh install of Ubuntu 20.04 and I am confounded with being unable to write a file with sudo. In Ubuntu 18.04, and I could simply do this: me@abcd:~/Desktop$ sudo echo “asdf” > /etc/ssh/got.txt Now, in Ubuntu 20.04, I get permission denied, even with sudo: me@abcd:~/Desktop$ sudo echo “asdf” […]

Categories
User Help

Centos 7 noexec to be removed from /tmp – tried google tips no luck

I did mount -o remount,exec /tmp still I see: mount |grep -i noexec|grep -i tmpfs tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,mode=755) tmpfs on /tmp type tmpfs (rw,nosuid,nodev,noexec) tmpfs on /var/tmp type tmpfs (rw,nosuid,nodev,noexec) tmpfs on /tmp type tmpfs (rw,nosuid,nodev,noexec) rebooted as well no luck === also tried new entry for /tmp on fstab & rebooted […]

Categories
Android User Help

How to prevent file corruption in SD card during unmount?

I have a custom device running Android 8.1. I am mimicking a partition of the internal flash storage to be used as a removable storage. At boot vold mounts the storage and creates the mount points. From an android app, I am able to use storage manager APIs to access the storage and perform operations […]

Categories
Android User Help

sdcard file corruption on unmount

I have a custom device running android 8.1, and I am mimicking a partition on the internal flash to be used as a removable storage. At boot vold mounts the storage and creates the mount points. From an android app, I am able to use storage manager APIs to access the storage and do mount […]