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The speed at which a program runs

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in RHEL-8.10 using NFS version 4.2 with all default settings, everything happening over port 2049, in /etc/nfs.com under [nfsd] there is threads=8. For a cluster whose head node has 2 Intel XEON cpu'...
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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% ...
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If you would open a listening socket on every possible TCP/UDP port (so thousands in total), without actually using them, what would be the cost in terms of performance? Is it merely an administrative ...
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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 ...
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why is NFSv4 so much slower than scp? mellanox 100gbps switch no load on two servers, just me, no load on the switch RHEL-8.10 x64-64 scp *tar 192.168.2.1:/data/ a.tar ...
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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 ...
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I recently upgraded the NVME drives on my workstation machine, from a pair of Samsung EVO 970 512GB drives to a pair of of Kingston Fury 2TB drives. All went well, and I even converted the machine ...
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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 ...
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Hello I use XRDP for multiuser and I have performance issue and connec issue. First, is about channel drdynvc if its set to TRUE I cannot connect from windows RDP client and can connect without issues ...
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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 ...
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I am trying to determine the libraries needed for pg_restore in the official postgres:15 docker image, but when I run ldd /usr/bin/pg_restore inside the container it returns this error: not a dynamic ...
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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 ...
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I am running the command dd bs=1M if=/dev/zero of=/dev/md7 status=progress. It started very slow at 4 MB/s but now has dropped to 1 MB/s. This is a standard SATA disk that was running perfectly ...
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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 ...
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I asked a similar question here : NFS v4.2 tuning with less than 50 servers on a closed infiniband [mellanox] HDR network switch all running RHEL-8.10: is there anything other than systemctl start ...
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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 ...
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I have 10 node deployment which implement red hat clustering software - pacemaker/corosync to mount gfs2 and ensure high-availability. Nodes are actually mail servers and use gfs2 to store user's data ...
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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 ...
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In the kernel I can use the work queues and create them with alloc_workqueue(...) and pass it a flag WQ_HIGHPRI for a high priority workqueue. I also see you can use apply_workqueue_attrs(...) for ...
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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 ...
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time touch /tmp/test.dat real 0m1.03s user 0m0.00s sys 0m1.02s A full second of sys-mode time to create a file in /tmp. That can become unbearable for ksh scripts that open dozens of files ...
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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 ...
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I have a nightly backup that transfers about 100gb of data from AIX server A to AIX server B using the following command in a script. tar cf - ./DATA | ssh server_b 'cd /DISKCOPY ; tar xf - ' This ...
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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 ...
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I'm experiencing extremely sluggishness in opening subshells (by using ` ` or $( ) command substitutions in scripts) while in ksh on some Linux servers. The same problem does not exist in sh or any ...
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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 ...
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I have up to terabytes of data (a large number of smaller files) that could contain wrong owner, group or permissions. To repair that we had a script doing sudo -n chown -R user:group "/path"...
jan's user avatar
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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 ...
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I want to do a bunch of tasks before and after the screensaver is activated in KDE (still using X11, since Wayland has too many flaws even after 10 years). So I made a custom script that is triggered ...
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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 ...
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Linux (and UNIX) filesystems featuring journaling are there to prevent filesystem corruption (any maybe file corruption, too). Some of them have mount options to control the details of journaling, and ...
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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, ...
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My home directory lives on an EXT4 partition. A while back, accessing this partition started to be delayed (disk sleep) to the point now where it has become painful It would appear to have something ...
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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 ...
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I have an host computer, set up with hostapd as access point and dnsmasq for DHCP server. I'm running under ArchLinux, with Linux kernel 6.1 (as I'm on an embedded ARM board which only supports up to ...
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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 ...
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I am using rsync to sync around ~2TB of data to a mechanical HDD-5400RPM. It's taking way too long. How can I improve the sync and check speeds to get as close as possible to maximum/optimal? Here is ...
atkuzmanov's user avatar
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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,...
Luis A. Florit's user avatar
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I got a case where I need to overwrite some file with another and noticed a very significant slowdown when using "mv -f" if the target already exists and is being read. More specifically, ...
Frederik's user avatar
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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 ...
LeoMan's user avatar
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I have recently wanted to mount a remote CIFS drive. But i have run into one major issue. The speeds are amazing. Uploading is about 220Mbit/s.. However, downloading has speeds of 5Mbit/s.. Which is ...
DEPSTRCZ's user avatar
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7 votes
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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 ...
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I use my computer for very CPU intense simulations, but no matter what I do the actual CPU frequency wont ever come close to hardware capacity. I have an i9-13900K, which maximum CPU freq. is 5.8GHz. ...
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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 ...
rampatowl's user avatar
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I have two files containing the similar pattern: cmd1 [cmd2 {xx/xx[7] x/x[0] ...}] cmd3 [cmd4 {xx/x[12] ...}] cmd5 [cmd6 {x/x[1] xx ...}] I don't need to consider all the cmds in two files. Only need ...
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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 ...
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I have a list of domains, a sample is: account.google.com drive.google.com google.com bgoogle.com yahoo.co.uk stats.wikipedia.org media.wikipedia.org files.media.wikipedia.org bible.com I would like ...
user avatar
1 vote
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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 ...
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I have a raspberry pi setup. When connected over ethernet ssh sometimes hangs, but generally works. When connected over wifi ssh is extremely choppy (8/10 connections fail, if I connect it drops ...
scosman's user avatar
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1 vote
2 answers
937 views

Until now, I used to backup my data using tar with one of the LZMA compression options (--lzma, --xz or --lzip) I recently noticed that 7-Zip has been ported to Linux in 2021 (https://www.xda-...
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