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Questions tagged [tmpfs]

69 questions
29
votes
4 answers

Performance difference between ramfs and tmpfs

I need to setup an in memory storage system for around 10 GB of data, consisting of many 100 kb single files(images). There will be lots of reads and fairly periodic writes(adding new files, deleting some old ones). Now, I know that tmpfs behaves…
Ivan Kovacevic
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1 answer

php script can't access /tmp folder

I have no open_basedir, php can access /etc /usr /proc /home etc… but not /tmp. tmpfs is mount on /tmp (/tmp type tmpfs (rw)) That's also the reason I want to use the /tmp folder. My files are owned by http (user for nginx and php) and readable by…
eephyne
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12
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5 answers

Low on space in /run

On Ubuntu Precise, I'm low on space in /run: admin@foo:~$ df -h Filesystem Size Used Avail Use% Mounted on /dev/sda1 19G 6.6G 12G 38% / udev 10M 8.0K 10M 1% /dev none 50M 40M 11M 79% /run none …
Brian
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9
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3 answers

Using tmpfs + a very large swap partition for /tmp instead of a regular filesystem?

I have Linux server and I have a spare 500GB disk partition. I wanted to format it and use it for /tmp. The server occasionally runs some large data processing tasks so it can happen that /tmp will hold GBs of temporary data. Then I got an idea that…
Petr
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7
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2 answers

Does Linux tmpfs filesystem need the sync option?

I'm looking for info about mounting a tmpfs partition and sync option. Sync makes the data beeing dumped onto the disk without beeing saved in cache. This works with ext4 and other filesystems. I'm wondering is even a tmpfs partition needs the sync…
Viktor Joras
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7
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3 answers

Tmpfs vs NVME SSDs from performance POV

I have a script that creates large temporary files. I'm inclined to use tmpfs for this, however I did a quick search for tmpfs performance and found this which reports speed as about 2GiB/s. Modern NVME SSDs have comparable speeds. Putting aside…
Peeyush Kushwaha
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6
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2 answers

Can I create a disk in memory for backups?

The biggest problem I have with my site is the 4 backup periods throughout the day where load will inevitably go above 50. I am using nice and ionice to try and reduce the impact but to only limited success. As I immediately copy my backup to an…
Christian
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6
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2 answers

Will noatime on a tmpfs volume improve performance?

I am using /run/shm/myfolder for nginx micro caching, also keeping ngx_pagespeed files there. I am wondering if there will be a speed increase if I go from relatime to noatime? It's for HDD, but on a tmpfs what will it change? tmpfs on /run/shm type…
cenk
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6
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2 answers

Is there ever a reason to use tmpfs instead of or in addition to zRAM?

I'm thinking about using zRam on my server. From what I've read about zRam, it apparently does everything tmpfs does and more. Once zRAM is working, is there any reason to keep tmpfs around? Is there anything tmpfs does that zRAM can't do? Is there…
David Cary
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6
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2 answers

Can a tmpfs become fragmented?

Since a tmpfs exists only in memory, can it become fragmented like memory can? Are there mechanisms to automatically defragment the memory, and thus increase - even slightly - the access speed of stored files?
Laurent Pireyn
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6
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2 answers

What can cause an increase in inactive memory and how to reclaim it?

I have heavy application running on a CentOS server and I'm seeing a strange memory behavior. Here is a snapshot of a munin graph: As you can see the amount of committed memory increases gradually causing the swap file to be use. What strikes me…
Boaz
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4 answers

How to check the content of swap memory in Linux?

I am trying to find out what exactly uses swap memory in my system. Free reports over 5GB of used swap memory, but all processes use only 24MB of swap. I suspect that swap might be used by a tmpfs filesystem, but I don't know how to check it. Would…
gbajson
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5
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2 answers

tmpfs fills up, although hardly used. How can I debug this

I have a system with / on tmpfs. Most / subdirectories have aufs mounted overlaying the read-write root filesystem with read-only base filesystem (the system boots from a read-only medium). Earlier, I used to use unionfs instead of aufs. It has…
Jacek Konieczny
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5
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2 answers

RHEL5: Can't create sparse file bigger than 256GB in tmpfs

/var/log/lastlog gets written to when you log in. The size of this file is based off of the largest UID in the system. The larger the maximum UID, the larger this file is. Thankfully it's a sparse file so the size on disk is much smaller than the…
John Kugelman
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4
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1 answer

Swap Memory Anomoly

I am currently experiencing a memory issue on my centos 7.6 distro. It began with my system swapping even though up to 80GB ram should have been available. free -m total used free shared buff/cache …
GreyStone
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