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4

I will try to answer questions as briefly as possible. The questions you are asking are usually addressed in introductory operating systems courses at universities but I will assume you have not taken such a course. Memory isolation for userspace processes is very desirable - not only to protect the kernel from malicious userspace programs, but also to ...


4

As it so happens, there is another significant interface with the kernel: the /proc and /sys virtual filesystems. While they do not hold regular files, their contents are direct gateways to the kernel: to act on them is to act directly on kernel-allocated memory. For instance, if you want to drop all memory caches, you may use... echo 3 > ...


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Unix has a plethora of locking systems. The one you found is called BSD file locking, but there are other file locking methods. On top of that, you also have semaphores, mutexes and more. As to your direct question, yes, it is a perfectly fine way to go. Don't worry about the time it takes. Locking is a high-overhead activity, by its very nature. This is ...


3

You can use find: find /usr -name '0914_Jul-2014.gz' -exec mv {} /var/tmp \; Or for extremely nested directory hierarchies find /usr -name '0914_Jul-2014.gz' -execdir mv {} /var/tmp \; Although as the documentation states you must ensure that your $PATH environment variable does not reference the current directory (namely .) if you use -execdir


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The sloppy means that the underlying mount system should ignore options it doesn't understand, instead of failing to mount altogether. This is usually used in combination with NFS automount, which leads to the second issue: the automatic remounting. automount is used to automatically mount a filesystem when it is needed, instead of having it mounted all the ...


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Great option :- you can try some more flavors also like xubuntu,lubuntu,and ubuntu unity Anyways Mint is also great and compatible with much devices their are some valid points also Cost cutting Linux is absolutely free Virus Free no need to install AV softwares Faster smoother and lighter believe me your experience will be awesome and some draw ...


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You have a good evaluation of well-known file systems at Phoronix. Well, of course, what you should use is entirely up to you as it is hard to not give an opinionated answer. As for your fears about Samsung, F2FS is open sourced and GPLv2. Hence in any case it'll remain forkable up to a certain point; see what happens with reiser4, for instance — regardless ...


2

bytes-per-inode determines how many inodes are created for that file system; inode-size determines how big each of those inode is. You need a lot of inodes if you intend to put lots of small files (&/or lots of directories) on the filesytem. AFAIK, you really only need inodes that are larger than the default size of 256 bytes if you want to store ...


2

As of Linux 3.18, the QNX4 filesystem driver only supports reading. (Source: the source). Ditto with QNX6. There's an alternate driver with partial read-write support, but it's been unmaintained for several years; you'll probably have to run an older kernel or tweak the code to compile it on a recent kernel. Alternatively, QNX supports reading ext2 ...


2

You can figure out the amount of packets received and transmitted across eth0 by running the following commands: cat /sys/class/net/eth0/statistics/rx_packets cat /sys/class/net/eth0/statistics/tx_packets You could then use this fact to write simple a shell script which will poll these files every second, and then calculate and output a PPS value (packets ...


2

There is no guarantee that another interface will route the traffic appropriately. Even if it does route to a device at the specified address, the device may not be the intended device. There are a number of issues which could arise: Changing the routing to another interface may inflict NAT rules on the traffic, which would break connections when the ...


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Since kernel 2.4 there is no difference between these cache types, there is only the page cache left.


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Checking for existence will reduce the problem, but in the most general case it's a race condition. The file could still be removed between the check and the copy attempt. Perhaps just capture all errors and drop any for "file doesn't exist". Normal copy: $ cp noexist bar /tmp cp: cannot stat `noexist': No such file or directory cp: cannot open `bar' for ...


1

You might do like: { command <doesntexist cp doesntexist 2>&3 ; } 3>&2 2>/dev/null It might be shorter in a subshell... ( <file cp file ... 2>&3 ) 3>&2 2>/dev/null But it still seems like a long way around doing... [ -r file ] && cp file ... All of those only test for readable files though - they won't ...


1

I expect that the files have more space allocated on disk than they are actually using. Normally I'd expect to see this only in binary files where blocks of NULLs are not stored. Since fastq format is text however I think the file allocation extends past the end of the data. Try the command ls -lsh and compare the two sizes listed for each file. Column 1 is ...


1

There's no way, unless you switch the complete UI to right-left mode via :set rightleft or $ vim -H. Even common workarounds such as using the signs column (which a plugin used to implement 'relativenumber' before that was built-in) won't do, as those appear on the left as well. The only, very clumsy hack would be a thin scratch buffer in a vertical split on ...


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VIM's Hebrew Mode will put the line numbers on the right, with set nu To start VIM in Hebrew Mode use vim -H Documentation here Warning: It does reverse your text to rightleft as well


1

Use locate to find the file: locate <file_name> Then use mv to move the file mv <location/file_name> <new_location/file_name>


1

Try DirectFB. It handles figuring out which operations can be accelerated in hardware for your display device.


1

L is not able to connect to B, but is B able to connect to L? You didn't say, but I will assume no. If A is your only way to communicate between B and L then you will definitely have to log in to A at some point. And also, the data will flow through A one way or another (which might be important if A is on a slow connection). You can establish an SSH ...


1

The spindown time -S 60 is equal to 5s*60 and corresponds to 300s. The APM levels -B 1-127 (permitting spindown) and -B 128-254 (not permitting shutdown) are more or less passed directly to the disk and hdparm doesn't do any further computation on those values. The exact behaviour of those values is unspecified and left to the drive manufacturer. Therefore ...


1

My solution to LUKS and keyboard layout problems is to add the passphrase twice. So the same sequence of key presses will be accepted in both US/qwerty layout and whatever you usually use (in my case, DE/qwertz). If you use more than one keyboard layout you can add more passphrases for them; LUKS supports up to 8 in total, and most people never use more ...


1

You don't need to install Expect on the server. Write an Expect script instead of running expect from a shell script. Have the Expect script itself spawn the SSH client, connect to the server and then loop through the numbers. To save yourself some effort you can record a session where you log in to the server and try some number with autoexpect. Save the ...


1

It depends. What do you mean by 'verify'? If you just want to monitor what syscalls some process is triggering then it's possible.. usually.... But if you feel like digging deeper then you're in trouble... I have not heard of any tools that could do that. You can use strace to see what syscalls some particular process is firing. Of course you'll have to ...


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Definitely go for Linux! Especially in a place where number of strangers will be using it... And I'd also suggest to make only terminals accessible for users (terminal server - terminal client model) to block them from physically accessing the machine itself. Users tend to browse in non secure sites, plug various USB devices with hell knows what evil living ...


1

If you share the storage as a file-share, no problems are to be expected. Think a CIFS (Samba) share or NFS from either the NAS appliance or from one server to another. If you share the disk as a block device, i.e. an iSCSI or Fiber Channel LUN you'll need a cluster aware file-system on top of that to facilitate concurrent read-write operations from both ...


1

You can do that through NFS. Mount the disk to a machine and share that drive through NFS to the other machine. Suppose the disk to be shared is /dev/sdb and the machines that you want to share the disk is machine1.example.com and machine2.example.com, then: Mount /dev/sdb in machine1 (You can skip this step if the said disk is already mounted and being ...


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You can easily achievethis via NFS Make NFS Share which can be read/write for user, you can find the guide for the same here


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In Setup > collectionLists add a new entry like below: (at the main menu just press S L A): here an example if you have a gmail account: Nickname : gmail-test Server : imap.gmail.com/ssl/user=your_user_name@gmail.com Path : View : The corresponding entry (gmail-test in this example) will be created and will be accessible at Folder List. ...


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I suspect that the bottleneck is writing to the USB flash drive. USB flash drives are typically at the low end of the performance/price range. Data accumulates in memory at 10MB/s up to a point, then gets written out at 200kB/s. You can try playing with the vm.dirty_bytes and vm.dirty_background_bytes kernel parameters. Setting them to a lower value might ...



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