I made a tmpfs filesystem in my home directory on Ubuntu using this command: Then I wrote this Python program: The result: I am confused about this result. Isn’t the tmpfs a file system based on RAM and isn’t RAM supposed to be notably faster than any hard disk, including SSDs? Furthermore, I noticed that this program is using over
Tag: solid-state-drive
Why io_submit(…, nr, …) might submit less requests than nr?
I’m using io_submit(…, nr, …) with nr up to 128 but I usually get fewer requests submitted. According to the manual IO_SUBMIT(2), this is legit but I wonder: why? Also, is there a way to know which request was submitted right away – without checking io_getevents()? From the manual: On success, io_submit() returns the number of iocbs submitted (which may
Decrease in Random read IOPs on NVME SSD if requests issued over small region
(TL;DR) On NVME SSDs (Intel p3600 as well as Avant), I am seeing decrease in the IOPS if I issue random reads over a small subset of the disk instead of the entire disk. While reading the same offset over and over, the IOPS are about 36-40K for 4k blocksize. The IOPS gradually increase as I grow the region over
Optimal way of writing to append-only files on an SSD
I want to know what’s the optimal way to log to an SSD. Think of something like a database log, where you’re writing append-only, but you also have to fsync() every transaction or few transactions to ensure application level data durability. I’m going to give some background on how SSDs work, so if you already know all this, please skim