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1answer
27 views

If tmpfs has bigger size than your RAM, how much RAM does it use?

If there is more tmpfs configured than the size of RAM, and there is a lot of stuff stored there in the tmpfs, how is the amount of RAM available to applications determined? If applications need more ...
1
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1answer
42 views

Why deleting big files from tmpfs is not instantaneous?

$ cat /proc/mounts | egrep ' /tmp ' tmpfs /tmp tmpfs rw,nosuid,nodev,relatime 0 0 $ dd if=/dev/zero bs=1M count=3000 of=/tmp/q 3000+0 records in 3000+0 records out 3145728000 bytes (3.1 GB) copied, ...
3
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1answer
47 views

change size of devtmpfs /dev/

My new kernel has CONFIG_DEVTMPFS enabled, and thus my /dev is mounted as devtmpfs. My old kernel was not using CONFIG_DEVTMPFS, and /dev used to be mounted as plain tmpfs. Now I have noticed, the ...
3
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1answer
130 views

How can I set up overflow /tmp partition?

I run Antergos as my OS. I have several drives in my computer: a 240gb SSD, a 320gb SATA hard drive, and a 120gb IDE drive. I store most everything on the SSD because I don't generally need more room ...
1
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1answer
42 views

migrating to systemd a startup-shutdown script that works with tmpfs and bindmounts

BACKGROUND INFORMATION : I have an init script that allows me to mount a folder to tmpfs, while bind-mounting the folder on drive to another location, so I can sync the contents (on startup, ...
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2answers
92 views

How to create “real” RAM disk that reserves memory

I've been shortly using this on Linux Debian Jessie to create a "RAM disk": mount -o size=1G -t tmpfs none /mnt/tmpfs But I was told it doesn't reserve memory, which I didn't know. I would like a ...
1
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1answer
27 views

Creating and mounting a RAM disk at computer startup

This is how I create RAM disk manually on Linux Debian Jessie: mount -o size=1G -t tmpfs none /mnt/tmpfs The question is how do I make this automatic at each computer startup? I have never created ...
3
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1answer
131 views

How safe is it to increase tmpfs to more than physical memory?

My server has 2GB RAM and 120GB SSD, plus some RAID arrays for storage. OS is Debian 8 (Linux 3.16). I have a MySQL intense application that has tmpdir = /run/mysqld, which is a tmpfs configured by ...
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2answers
85 views

Tmpfs mount for directories on another partition

I have /var on a 10Gb EXT4 partition separate from /. I want to stick /var/cache in RAM using tmpfs. The /etc/fstab entry would be quite simple: tmpgs /var/cache tmpfs ...
3
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2answers
130 views

Swap on tmpfs (Obviously a bad idea, but is it possible?)

This question originated with a joke between co-workers about increasing performance by moving swap partitions to a tmpfs. Clearly even if this is possible, it's not a good idea. All I want to know ...
1
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2answers
123 views

What is going on with Google Chrome and deleted files

Debugging some CouchDB problems, I was looking for (still open) deleted files: $ lsof -nP | grep '(deleted)' And to my surprise I found that Google Chrome has around 16900 such files: 15870 files ...
5
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1answer
840 views

mount /var/log as tmpfs in Linux

My current laptop hard drive (Seagate ST940818SM) is slow (max 42MB/s R/W speed) and out of space. Mounting /tmp and /var/tmp as tmpfs does a lot of performance improvement. So is it safe to mount ...
3
votes
1answer
205 views

What happens when a tmpfs volume is full and swap is full? Is Linux's OOM-killer involved? [duplicate]

I understand that if a persistent / disk-based volume is full, files need to be explicitly deleted to free up space before more can be added. Further, I understand that if memory is exhausted, the ...
9
votes
1answer
551 views

What sets the size of tmpfs? What happens when its full?

What sets the size of the tmpfs? (On my machine it resides in /dev/shm) I can see its entry in /etc/fstab, but no notation of its size. When checking with df -h, it seems to be half the size of the ...
3
votes
1answer
60 views

How do I lock a growing directory in memory?

I want a directory to be fast to read from, like on tmpfs for some time. The closest thing is this: vmtouch -L -m 2G /path/to/mydir But this does not detect new or deleted files.
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0answers
30 views

Permission to execute denied for every file in /tmp: [duplicate]

When I try to execute any program from the /tmp directory, it shows me /tmp/file_name: Permission denied. The same error is shown when I simply enter /tmp. The file system for /tmp is ramfs. I've ...
4
votes
2answers
73 views

Can I mount a case-insensitive tmpfs/ramfs?

I would like to utilize the performance of tmpfs/ramfs for some file operations, but the programs/processes that use these files assume a case-insensitive file system. I cannot find any documentation ...
3
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2answers
491 views

Per user tmpfs directories

Using the shared /tmp directory is known to have lead to many security vulnerabilities when predictable filenames have been used. And randomly generated names aren't really nice looking. I am ...
1
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0answers
376 views

How are ownership and permissions of tmpfs folders created via /etc/fstab determined?

I've created a folder /mnt/ramdisk. I've got the following line in /etc/fstab to create the ramdisk at startup and mount it to /mnt/ramdisk: tmpfs /mnt/ramdisk tmpfs ...
1
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0answers
234 views

tmpfs : creating file in tmpfs does not change memory usage in htop/top

I read about tmpfs and got curious to get the benefits from it. So, I created a directory and mounted as tmpfs. So, as per theory, whatever is written in tmpfs gets stored on RAM directly and lasts ...
7
votes
2answers
2k views

Difference between /run and /var/run

Is there any difference between /run directory and var/run directory. It seems the latter is a link to the former. If the contents are one and the same what is the need for two directories?
0
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1answer
195 views

root cannot access virtual filesystem? [duplicate]

When attempting to check my disk usage under / I found that root did not have access to certain virtual filesystems. I also could not check the permissions on the virtual filesystem. Why is this? ...
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0answers
59 views

unlimited tmpfs

How to have the advantages of tmpfs and not be limited to its small size? I'm thinking of a shell script that runs as a daemon, monitors RAM and adds more swap files in specified folder, when memory ...
2
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0answers
166 views

Using shared memory through tmpfs and NUMA on x86_64/Linux

Here's what I'd like to do: put a file on tmpfs but ensure that all of it (all pages of it) ends up on the same NUMA node. First, I thought this would be trivial: I'd just mmap() a tmpfs file with ...
2
votes
1answer
373 views

What happens when a tmpfs is full and no swap space is available?

Let's say I have a setup with 16 GB of physical RAM, A tmpfs of max. 8 GB containing a file with 5 GB and A swap sized 4 GB. If I'd try to, e.g., create a copy of the 5 GB file on the tmpfs, what ...
3
votes
1answer
831 views

How to compress a TMPFS folder?

I'm looking for a way to compress a tmpfs folder on the fly. I would like to use it for a local cache folder with a lot of data. I know there is a way to use Redis with eg LZF compression, but I ...
7
votes
2answers
278 views

How to make files inside TMPFS more likely to swap

I'm using tmpfs for my /tmp directory. How can I make the computer decide to swap out the files inside the /tmp before swapping out anything that is being used by applications? Basically the files ...
0
votes
2answers
397 views

Ramdisks in OpenSuse 13.1

I've just installed OpenSuse 13.1, and noticed 5 tmpfs ramdisks in the partitioner, mapped to /dev/shm, /run, /sys/fs/cgroup, /var/lock and /var/run. I don't remember seeing these ramdisks in the ...
0
votes
1answer
319 views

should I reduce /dev/shm size?

I have a server wity 8 GB RAM Mem: Total 8031464 Used 5146344 Free 2885120 If I execute # df it always returns this tmpfs 4015732 0 4015732 0% /dev/shm What does it ...
5
votes
1answer
885 views

Does tmpfs automatically resize when the amount RAM changes, and does it compete when there's multiple tmpfs?

If I have a tmpfs set to 50%, and later on I add or remove RAM, does tmpfs automatically adjust its partition size? Also what if I have multiple tmpfs each set at 50%. Do multiple tmpfs compete ...
0
votes
1answer
633 views

How do I make a tmpfs mountpoint persistent across reboots?

If I create a ram disk on cent os using tmpfs will it go away on restart? I know the data will go away (I would assume), but will it still survive a reboot? I am going to allocate a ram disk for use ...
12
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3answers
4k views

On system memory… specifically the difference between `tmpfs,` `shm,` and `hugepages…`

I've been curious lately about the various Linux kernel memory based filesystems. Note: As far as I'm concerned, the questions below should be considered more or less optional when compared with a ...
3
votes
3answers
2k views

How can I check to see if the /tmp directory on my CentOS 5.x system is mounted on tmpfs?

CentOS 5.x My understanding is that the contents of /tmp/ in CentOS 5.x can/are automatically purged by the OS via one of two methods: A daily cron task running tmpwatch If /tmp/is mounted on a ...
0
votes
1answer
799 views

Should tmpfs be unmounted at system shutdown?

Assume I have a linux system with the following partitions mounted (beside root): proc on /proc devtmpfs on /dev devpts on /dev/pts tmpfs on /dev/shm sysfs on /sys tmpfs on /var/run tmpfs on ...
1
vote
1answer
827 views

special device tmpfs does not exist

I'm trying to speed up a project which uses a folder for cache by mounting the cache folder on tmpfs. But whenever I mount it I get this error message: mount: special device tmpfs does not exist ...
13
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1answer
1k views

Why is /dev full?

The /dev.. is full: SERVER:/dev # df -mP /dev Filesystem 1048576-blocks Used Available Capacity Mounted on udev 12042 12042 0 100% /dev There is no ...
1
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2answers
365 views

mount tmpfs preserve current permissions

I have a directory of a web application cache and this has the permissions 755 (default), and I configured setfacl additional permissions. the problem is that when I restart the system, the ...
3
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1answer
9k views

Can fstab options uid and gid be the user-group name or must they be numeric?

I'm learning how to set up a tmpfs in fstab for my www-data user and I was wondering if I can use the actual user/group name instead if the numeric ids (personal preference)? I'm on Debian with ext4, ...
0
votes
1answer
139 views

Execute in Place an encrypted ram drive

I have found a few old posts claiming that tmpfs can execute in place. Is this true? If so, how? If not, is there a ram drive alternative? Can this be done with a ram drive that is encrypted? If ...
0
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2answers
116 views

are daemon tmpfs executables copied unencrypted to memory upon execution? (prevent if so?)

When a daemon is executed, is the executable copied to memory? If so, can it be copied encrypted? If not, is there a way to prevent the executable from being copied to memory? The executable is ...
0
votes
1answer
226 views

How can I use the tmpfs to accelerate my chrome browser start up?

Every time when I am trying to start the chrome browser, it is a little bit slow because the chrome need to load the cache and that may cause a big amount of disk IO. My distribution is Debian ...
6
votes
1answer
4k views

use `/run/shm` (formerly `/dev/shm`) as a temp directory

Is it good practice to create a directory in /run/shm (formerly /dev/shm) and use that like a temp directory for an application? Background: I am writing black box tests for a program which does a ...
2
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0answers
383 views

Moving /dev/shm/ to /run/shm in Arch?

Dolphin (The KDE4 FM) would not receive file change notifications for /dev/shm, but for /run/shm. So now I would like to migrate /dev/shm/ to /run/shm, but I couldn't find the corresponding part in ...
1
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1answer
303 views

What parts of the filesystem to tmpfs/squashfs/sparseimage for USB live system

I want to create a live system on a USB key / SDCard with Linux Mint 14 (KDE or Debian Edition) that stores data persistently. The USB key needs to have at least one fat32 partition. As storage for ...
2
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1answer
436 views

tmpfs performance

I use avconv to make screen recording of gameplays on linux (yeah, I'm sorry, I am one of them, but I get more excited about the scripts than playing it self), but recently my harddrive has gone and ...
3
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1answer
771 views

Does the (source) device in a tmpfs type mount mean anything?

I just went into /etc/fstab (Linux) and changed my line for /tmp (on which a specific ext4 partition was previously mounted) to tmpfs. This was clearly a bit silly, but I wasn't thinking. Anyway, I ...
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3answers
11k views

Move /tmp to RAM

I am trying to move /tmp to RAM and obey good practice: /var/tmp should NOT be placed in tmpfs, as it must survive reboots not mount /tmp as a stand-alone tmpfs, but rely on /dev/shm or /run/shm ...
7
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3answers
3k views

Proper way to disable tmpfs on /run/shm

How do I disable tmpfs on /run/shm? I searched through initscripts and found that the following code checks the entry in fstab, but what should I change to make it not mount /run/shm? I'm running ...
8
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1answer
3k views

Tmpfs only with RAM

How to be sure that a tmpfs filesystem can only deal with physical and it's not using a swap partition on disk ? Since i have a slow HDD and a fast RAM i would like, at least, giving higher priority ...
2
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2answers
201 views

Graphical archive manager that uses /tmp

I am looking for a (preferably) graphical archive manager that can be configured to use /tmp as a scratch area for decompressing. My setup is as follows: I have my local workstation with /home ...