Category: QA

Questions and answers.

mmap a large range of memory which is larger than the total size of physical memory and swap

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How to make mmap() a large range of memory which is larger than the total size of physical memory and swap successfully? Short answer: Adding the MAP_NORESERVE flag to mmap() to make it not reserve any swap space for the mapping. For example: rr_addr = mmap((void*)i, len, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE|MAP_NORESERVE, -1, 0); More details in: http://stackoverflow.com/questions/4803152/mmap-fails-when-length-is-larger-than-4gb

Managing LVM

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Any tutorials or tips on how to manage LVM? LVM provides a flexible and easy way to management storage disks on Linux. It also provides a set of tools for management. Here are some tutorials and references for managing LVM: LVM man pages: https://www.systutorials.com/docs/linux/man/8-lvm/#lbAL Manage Disk Volume in Linux: http://www.hongkedavid.com/blog/disk_volume.html LVM with Xen: https://www.systutorials.com/b/linux/tag/lvm/ Remove missing phyiscal volumes
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No battery status icon on the top panel in Gnome Shell

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  The battery icon in Gnome 3 Gnome-shell is missing. How can I fix it?   The system-monitor extension ( https://extensions.gnome.org/extension/120/system-monitor/ ) has a option to enable/disable the battery icon. This extension also shows the CPU/memory/network status which I miss as in Gnome 2. Great extension! The upower service may fail to start if an iPhone is
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