Questions tagged [performance]
The speed at which a program runs
1,062 questions
1
vote
1
answer
38
views
Linux fixing slow usb transfer speed without rebooting
I have a usb 3.0 apricorn usb disk, 1tb size I think, for which this has been done to it under RHEL-8.10 and is only used on servers running RHEL-8.10 :
parted /dev/sdb
mklabel gpt
mkpart primary 0% ...
- 9,175
1
vote
1
answer
130
views
why is rsync slow compared to cp
I asked the question yesterday of why is NFSv4 so much slower than scp.
I narrowed down things a bit, my real question now is why is rsync slow compared to cp ? as I don't think NFS is a factor. I've ...
- 9,175
2
votes
2
answers
125
views
How can I see how much space was freed by trim on an SSD?
In my current setup, I have three different filesystems on two different SSDs: A FAT partition and a BTRFS partition on one drive, and ext4 on a second drive. When running fstrim, the output is ...
- 202
2
votes
2
answers
877
views
XRDP poor performance for streaming videos
I don't know what to do I spend around 2 weeks setting up XRDP. I have XRDP up and running with Xorg on a 64 core epyc 3 gen. and performance is terrible. The machine's main usage should be as a ...
- 53
1
vote
2
answers
306
views
Installing Kali Linux on a external HDD, dual-booting with Windows 10
I have Oracle VM on my Windows 10 laptop and installed Kali Linux on it.
But after using the VM several times, Kali Linux crashes and does not launch.
So, I decided to install Kali Linux on an ...
- 331
2
votes
0
answers
65
views
dm-crypt IOPS amplification
I have a ZFS pool comprising a mirror comprising two partitions encypted with dm-crypt.
$ zpool list -v data2
NAME SIZE ALLOC FREE CKPOINT EXPANDSZ FRAG CAP DEDUP ...
- 1,403
2
votes
0
answers
58
views
Why is my ZFS read performance tanking for RND4K reads and writes compared to an XFS partition on the same drive?
I have a pair of NVMe Crucial P5 Plus partitioned with an mdadm RAID1 partition formatted as XFS for / and another ZFS RAIDZ1 partition for the remainder of the disk.
Performance of the XFS partition ...
- 2,851
2
votes
2
answers
104
views
Recovery of a compressed image not possible due to lack of Space - general understanding of compression methods
I used gzip to compress an image which is quite huge still.
dd if=/dev/sda2 bs=1M | gzip -c -9 > sda2.dd.img.gz
then I changed the partitioning of the Drive because I wanted to install Linux.
And ...
2
votes
1
answer
160
views
Should I use physical or logical sector size with LUKS?
I have an external HDD (not ssd) which reports:
Sector Sizes: 512 bytes logical, 4096 bytes physical
Should i use --sector-size 512 or --sector-size 4096 with cryptosetup LuksFormat? Using ...
- 953
2
votes
1
answer
121
views
Make parameter substitution in newline-separated string more efficient
The following code should demonstrate and help with testing inefficient Pattern Matching expressions in a Parameter Substitution for a newline-separated strings var vs. array.
The goal is to achieve ...
- 69
1
vote
0
answers
167
views
sysfs missing CPU thermal_throttle information
Background Information:
I'm running Ubuntu 24.04.1 LTS (Noble Numbat, kernel 6.8.0-51-generic) on an AMD Ryzen 9 7950X3D, and I'm investigating some odd behavior where the CPU governor/driver will ...
- 11
0
votes
1
answer
603
views
NFS v4.2 tuning
https://www.youtube.com/watch?v=JXASmxGrHvY
at 5:30 the statement is made
if you get NFS tuned just right it is incredibly fast for ultra small file transfers*...
at 6:05
I've heard of 4.0GB/sec ...
- 9,175
0
votes
1
answer
262
views
Speeding up curl in bash scripts
I'm using a Bash script to retrieve the Spotify album thumbnail from whatever I'm listening at the moment to show it as an image in Hyprlock.
For this particular case, I'm using the command curl to ...
2
votes
0
answers
111
views
Speed up memory allocation
We have some servers CentOS 7 with 1Tb RAM for large math calculation.
When server is just rebooted, at application start memory allocation is realy fast
When some calculations were already performed ...
- 63
0
votes
0
answers
48
views
What is the meaning of columns in the table displayed by cpupower-monitor?
Running sudo cpupower monitor on Ubuntu 24.04 I'm getting:
| Nehalem || Mperf || RAPL || Idle_Stats
CPU| C3 | C6 | PC3 | PC6 || C0 | Cx | ...
- 151
1
vote
1
answer
187
views
Failed to run some functions with perf tool in embedded Linux
I am working on an embedded Linux system (kernel-5.19.20), and I tried the perf tool in my SOC, found some functions did NOT work.
After run perf record /test/perf_test, I got the perf.data, and perf ...
- 651
1
vote
1
answer
596
views
`pzstd` = parallelized Zstandard, how to watch progress in 4TB large file/disk?
I am brand new to zstd/pzstd, trying out its features, compression, benchmarking it, and so on. (I run Linux Mint 22 Cinnamon.) This computer has 32 GB RAM.
The basic command appears to be working, ...
- 31.3k
1
vote
0
answers
103
views
preventing Linux session unresponsiveness during heavy NFS write
Given this scenario:
on a 100gbp infiniband LAN, (same happens over the 1gbps LAN)
a RHEL-8.10 host controller server having a SCSI cable connection to an enterprise type data storage unit that ...
- 9,175
0
votes
1
answer
252
views
Debian - Terrible Performance on MacBook Pro. LUKS Related?
Two days ago I did a fresh install of Debian 12 stable + Xfce on my Late 2013 MacBook Pro using LUKS for full-disk encryption. Performance around the OS has been incredibly poor. My CPU is hardly ...
- 11
0
votes
1
answer
318
views
Encrypted LUKS fs inside a file: sparse or not?
I have a LUKS encrypted file filled with around 160 GB of data
that I use a lot. For safety, I created the file with 400 GB.
That is, of course, a lot of wasted space.
So I switched to a sparse file,...
- 519
1
vote
2
answers
583
views
accelerate re-syncing for a large file (> 3 TB) with rsync
How to accelerate re-syncing large file (>3 TB) which got few of its blocks changed (< 1 GB) with rsync.
AFAIK, rsync will do checksum comparison between src/dst blocks to find the differences ...
- 111
7
votes
4
answers
1k
views
Simulate slow disks in KVM to see effect of LVM cache in test setup
I'm setting up a Linux system in KVM (QEMU) to test the effect of adding a writeback LVM cache on a fast disk in front of a logical volume that resides on a set of very slow disks (a RAID1 LV). This ...
- 356k
0
votes
1
answer
389
views
Intel turbo boost all core clock speed in practice
My understanding is that Intel's quoted "max turbo boost" speed is only guaranteed when a single core is active, and that when all cores are active, the clock speed could conceivably fall to ...
- 113
0
votes
2
answers
224
views
why is all this swap space being used?
I have a Debian box, where I am doing some data recovery using ddrescue on a sata ssd. The process has been running for 24 hours, and has 24 to go (at least)
in any event, the PC has 16GB ram, and ...
- 3,979
1
vote
1
answer
571
views
ZFS dataset encryption on top of LUKS
There has been discussions about using ZFS on top of a LUKS-encrypted partition vs. using ZFS's native per-dataset encryption. However, they are always presented as either-or.
My question is about ...
- 895