All Questions
Tagged with filesystemscache
52 questions
2votes
1answer
44views
How to prioritize SSD page cache eviction over HDD with slower speed?
I have a large slow HDD and a small fast SSD. This is about reads not RAID. My desktop grinds to a near-halt when switching back to Firefox or man pages after (re/un)-loading 12+ GiB of Linux kernel ...
- 195
6votes
3answers
1kviews
Does linux have a cache for standard output?
I know that recently accessed files are cached into the RAM, but is there a cache for frequent commands? For example, if I run cat file.txt multiple time, file.txt will be cached after the first ...
- 135
0votes
2answers
73views
Is it possible to get a higher memory buff/cache usage after writing a lot of data to the disk?
On an Apache server of my own, logging requests to files has been enabled using a custom Apache module. The log files can reach several GB at the end of the day. Using Nagios I have noticed memory ...
- 101
0votes
1answer
239views
Question on tuning file system cache in Linux UBIFS on MTD
I am working on an embedded Linux system, where kernel is 5.10.24, and UBIFS on MTD is used. The testing team had a test, which writes a disk file (open, write, close in order), then powers system off....
- 591
1vote
0answers
66views
Clean ways to prime the kernel inode cache after boot?
Various answers on various StackExchange sites cover parts of this topic, but I did not see an exact match for this scenario. How can you identify every mounted standard filesystem, and traverse all ...
3votes
0answers
78views
How do I undo copying a file that is ended up in cache?
I have copied a large file to USB drive. The file appeared to be copied almost instantly, but copying operation stalled at the very end. /proc/meminfo is showing large, gigabyte Dirty: entry which is ...
- 5,983
1vote
1answer
84views
How to purge in-memory disk cache
Linux uses free RAM to store pages of disk files to speed up overall disk access. However for the purposes of benchmarking, I want to test the disk read speed and I don't want that speed measurement ...
- 111
0votes
1answer
227views
The reason why buffers in "free -h" command output is increased
I did two experiments. The first experiment (Ubuntu 20.04, ext4 filesystem): Run command free -h -w: $ free -h -w total used free shared buffers cache ...
1vote
0answers
1kviews
Why I don't see any increase in "Dirty" memory when writing to a file?
I read a bunch of stuff about "Write-back" mechanism today and wanted to try an experiment. EDIT: file downloaded from the Internet shows up in Dirty stats Based on the comments, I tried to ...
1vote
1answer
125views
Is it possible to create a cache directory that refuses unlink/delete?
I have a cache directory that stores files that should never change once downloaded. However, the program that uses this cache directory deletes the files from the cache. Is there any mechanism (like ...
- 34k
3votes
0answers
143views
Prevent disk spinup by regular directory read access
I have a hard drive which is configured to spin down on inactivity. Unfortunately, a regularly (~every 15 min) occuring directory read access wakes up the disk from its slumber. When there is no ...
- 191
1vote
2answers
487views
Linux page cache consistency
I have a couple of general questions regarding the Linux page cache. As I understand, there are (at least) three methods a block on a block device can be related to a block buffer in page cache: by ...
- 605
1vote
1answer
44views
Removing directories not accessed in X days
I have written some scripts for downloading and caching music, and I like to delete the directories in the cache location that have not been accessed in X days. I can do that via: gfind "$music_dir" ...
- 1,684
2votes
0answers
305views
Does the Linux Page Cache (Buffer Cache) only cache the files' clusters (pages) or does it also cache the Inodes (metadata)?
The Linux-Kernel implements a Page Cache (often also called Buffer Cache) to speed up the file systems of the underlying storage devices. Does the Page Cache only cache the pages or clusters of files ...
- 485
2votes
0answers
28views
Find the size of all relevant caches when doing I/O
So, I'm looking at the stats from iostat, which updates every few seconds, and I see that I/O to device happens in bulks, say, around 40M/s, once every half a minute or so. I'm debugging an ...
- 617
