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Questions tagged [nvme]

93 questions
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attempting to read the same file from multiple threads causes the file to become corrupt?

I've written a python script that uses opencv to read images off a drive, do a little bit of processing, and store them in a buffer. To speed it up, I created a multithreaded version using python's "threading" package that spawns a bunch of workers…
cytokinesis
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User-mode application that performs RDMA directly to nvme drive on Linux

We've been developing HPC applications that take advantage of the infiniband infrastructure. One of our applications exchange data that is stored in an nvme cache with other nodes, and for that it uses RDMA posts. We think we can increase the…
Caian
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Why can't my U.2 drive work in a PCIe x16 slot, but works in a PCIe x4 slot?

I am currently experiencing an issue regarding my U.2 drive and PCIe slots, and I hope those who have had a similar experience can help. I have used a PCIe adapter card to connect a U.2 drive to my computer. If the drive is connected to the PCIe x4…
Moon soon
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How to write a raw data in physical memory to NVMe ssd using kernel module?

I am currently looking for an implementation which directly writes data in kernel dma buffer into NVMe SSD with good data speed. I have looked in SPDK library which operates in user space. Is there any way to directly map the DMA memory in kernel…
Kamal
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Where to start with PCIe C source code for creation of NVMe submission and completion queues

I am reviewing the NVM Express Base Specification, Rev. 1.4 Paragraph 7.2 Command Submission and Completion Mechanism (Informative) and wondering where to start (examples) with a C code solution to establishing the Submission and Completion Queues…
mpatch54
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Concurrent mmap page faults failing to use NVMe IO queue on Linux?

I have a database-like service that serves queries from an embedded key-value store (LMDB), where the data is 1. orders-of-magnitude larger than main memory; 2. rarely written to/updated (once per hour or less), 3. heavily read by many concurrent…
tsutsu
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Can I use the local NVME drive on the Microsoft Azure Lsv3 machines for SQL TempDB?

These storage optimised VMs have a 1.8 TB NVME drive attached. It is a ephemeral drive(eg. it is lost when the VM is stopped/deallocated). I can't really understand the use of this drive at this moment. I could not find any concrete use for this…
Mitz
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mmap() NVMe cmb resource file and memcpy() to it, with the unplugged SSD still could write

I mapped cmb resource file and wrote data to it. When I unplugged the SSD, I thought that a SIGBUS should be generated but the program was still running. So was this a normal behavior? Linux kernel: v5.15.88 OS: Centos 7.4 CPU: Intel(R) Xeon(R)…
octaves simple
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Do we need surprise hotplug support to remove device and rescan bus through sysfs?

We have a NVMe SSD that requires a power cycle (because of firmware updates that does not work with controller reset). We are exploring using NVMe subsystem reset. But our platform does not support surprise hotplug, so we are trying to use sysfs to…
duncanthetall
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I can't find a NVMe driver for my new M2 Samsung 980 PRO (W10 pro 22H2)

I am using a new M2 Samsung 980 PRO. Samsung Magician says there is a unknown NVMe driver installed. I tried to do a backup based on DISM with Heise C'T wimage. Some files are corrupt, thats why backup fails. I simply would like to install a…
Robert Buk
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Mariadb in raid 10 NVME SSD slow read speeds

It would seem to me that we have a bottleneck we just cant seem to get over. We have a setup which contains 4 NVME drives in Raid 10 We are using mariadb 10.4 We have indexes The workload that we have will 99% of the time be IO bound there is no way…
Joséph Flames
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API for NVMe driver

I am new to storage servers. Is there any API available to communicate with NVMe driver? Recently i came across IOCTl and SPDK, but i didn't get a clear idea about how to use the same. Does NVMe passthru command come under IOCTL? tried to do nvme…
SHEKHA SHOUKATH
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Linux direct IO latency difference between reading 4GB and 32MB file under pread in NVME

My test will randomly read 4K pages (random 4k page at time in a tight loop) in both 4GB and 32MB files using direct IO (O_DIRECT) and pread on NVME disk. The latency on 4GB file is about 41 microsecond per page and the latency is 79 microsecond for…
Kenneth
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Ubuntu 20.0.4 server install didn't use whole NVMe drive

I installed Ubuntu 20.0.4 LTS onto a fresh Samsung 250GB NVMe and used all the defaults during installation. Everything seemed to go fine but I'm not seeing that it is only showing ~100GB on the drive. How do I extend the partition $ df…
Fred
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There is no json.h in \usr\include\json-c directory ' ../nvme.h:26:10: fatal error: json.h: No such file or directory'

There is no "json.h" in "\usr\include\json-c" directory. Is there an application that I have to install? I have installed "sudo apt-get install libjsoncpp-dev," but it is not working. ubuntu@nvme-cli:~/nvme-cli$ ninja -C .build ninja: Entering…
Hossein
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