All Questions
107
questions
2
votes
1
answer
101
views
Unable to get my rsync of my software RAID 6 past 40MB/s. Looking for suggestions
Wondering what I could adjust to get my RAID 6 Software Raid to resync quicker. Currently it's proceeding at max of 64MB/s and averages to something around 25MB/s. Hoping to get it to 200MB:
[...
0
votes
1
answer
403
views
How to combine an SSD with two HDDs in a RAID1-ish hybrid setup?
Coming from Linux SSD as HDD cache, I'd like to set up an SSD (or rather a partition thereon) as cache for basically a RAID1 of two HDDs. But since the data might remain cached on the SSD for while, I ...
- 388
0
votes
1
answer
141
views
Does daily rsync OS backup push SSD drives to its limits?
Since past year I'm using Rsnapshot (which uses rsync) to do my daily laptop Linux Ubuntu OS backup to a local NAS.
Some months ago I started having serious problems with the OS stability. It seems ...
- 256
0
votes
1
answer
2k
views
Why does fsck not working when I try to repair the filesystem
I try to mount /dev/nvme0n1p1.
Disk /dev/nvme0n1: 465.76 GiB, 500107862016 bytes, 976773168 sectors
Disk model: Samsung SSD 980 PRO 500GB
Units: sectors of 1 * 512 = 512 bytes
Sector ...
0
votes
0
answers
40
views
How to mount a used ssd to a linux server
I want to use my secondary ssd onto my server (the ssd was earlier was used on the same server before the OS on the server was reinstalled). How to mount the ssd so that I can use the old data?
2
votes
1
answer
4k
views
lvmcache/dm-cache writeback cache full performance
I have a SSD writeback cache in front of a HDD, set up through lvmcache (so a dm-cache). When the cache LV is not full (Data% column in lvs < 100.00%), writes go to the cache device (monitored via ...
- 23
0
votes
0
answers
213
views
What's the best means to clone the root linux hard drive to a new drive?
I bought a new enterprise grade SSD to replace my Samsung SSD. It was $500, not cheap. Anyway, the purpose is to have a more reliable and longer-lasting root hard drive, since a non-enterprise drive ...
- 103
2
votes
2
answers
709
views
md raid5 extremely slow on discard
Hi all md raid experts
Running Centos 8 (with all latest updates, kernel 4.18.0-240.1.1.el8_3.x86_64) where I have 3x2T Samsung SSD 860 QVO 2TB in raid5 (to be used as base for some KVM VMs) and when ...
- 121
2
votes
0
answers
403
views
preventing big HDD's to spinup by using (small) SSD's as cache
I want to build a NAS that is as quiet, efficient and cool as possible.
In this scenario, I have the following parts:
-4 SATA connections to the motherboard.
-2 Hard drives, one is 1TB, the other is ...
- 21
3
votes
5
answers
3k
views
Linus/ext4/nvme crashes during high io
During mvn compilation, I have random crashes.
The problem seems related to high IO and in kern.log, I can see things like:
kernel: [158430.895045] nvme nvme1: controller is down; will reset: CSTS=...
- 151
1
vote
1
answer
643
views
How do I know if SSD is the bottleneck in Linux?
I have a database server which uses a Samsung 840 pro disk. The load is constantly higher than usual, even if there is not much activity on the website. So I suspect the disk has worn out. But how can ...
- 113
0
votes
1
answer
2k
views
Can't resize ext4 partition
I have an 500GB HDD disk (480GB free) that I need to clone it to an SSD 240GB.
I have read that cloning the HDD to the SSD should work for NTFS filesystems. But it isn't working for the ext partition....
- 121
3
votes
2
answers
1k
views
Is swap compression in RAM (ZSWAP) benefitial on a Linux server with SSD drives?
I am trying to improve performance (responsivity) of a webserver during rare events of high memory utilization (90%...) where it starts to swap a lot, in order to help manual intervening faster and ...
- 282
26
votes
2
answers
20k
views
Linux SSD as HDD cache
I have a Linux server system installed on an SSD and an HDD for user data. As there is space left on the SSD, I want to use it as a read cache for the HDD.
Looking at the possibilities, I found:
dm-...
- 431
-2
votes
1
answer
367
views
SSD disks VS SATA disks and SAS disks [closed]
as all know there are many type of disks
while the famous are
SSD disks
SATA disks
SAS disks
dose SATA/SAS disks can be nearly as SSD disks? about IO and performance?
how much SSD disks are ...
- 461
0
votes
1
answer
222
views
Dose zookeeper servers must use SSD disks?
we want to install kafka cluster and 3 zookeeper servers
kafka should use the zookeeper servers in order to save the metadata on the zookeeper servers
ZK Data and Log files should be on disks, which ...
- 461
3
votes
2
answers
893
views
Low random read IOPs for 5 SSDs in hardware RAID5 setup
We have 5 Toshiba Px04Srb192 SSDs (270K random read IOP as per spec), setup in hardware Raid5. Running fio is giving 250K IOPs which is much below what I was expecting.
/fio --randrepeat=1 --...
- 31
3
votes
1
answer
1k
views
Can consumer SSD over-provisioning improve performance?
While reading up on ways to improve SSD endurance, I came across an Intel whitepaper on the subject of SSD over-provisioning (limiting the host-adressable space on a drive or not including some of the ...
- 31
1
vote
0
answers
255
views
Difference in utilisation reported by iostat for two identical disks in RAID1
I'm trying to debug some weird behaviour with Postgres performance and am trying to understand the iostat output. I'm on 2x SSD on RAID1. Why would one of the disks be reported at ~21% utilisation ...
- 489
1
vote
0
answers
2k
views
NVME vs SSD: Read/Write performance issue
We have rent some servers from Hetzner.de. A few of them have NVMe hard disks while the others have SSDs.
We becnchmarked the read/write performance on 4 of our servers using the following commands:
...
- 203
6
votes
1
answer
8k
views
Poor write performance of software RAID10 array of 8 SSD drives
I have server with Supermicro X10DRW-i motherboard and RAID10 array of 8 KINGSTON SKC400S SSDs; OS is CentOS 6
# cat /proc/mdstat
Personalities : [raid10] [raid1]
md2 : active raid10 sdj3[9](S) ...
6
votes
1
answer
4k
views
SSD IOPS on linux, DIRECT much faster than buffered, fio
I have a 30Tb-sized hardware RAID-6 system (LSI 9280-8e) of 10 DC-S4500 Intel SSDs that is used for database purposes. The OS Debian 7.11 with 3.2 kernel. The filesystem is XFS mounted with nobarrier ...
- 185
0
votes
1
answer
55
views
I want to delete exiting partition on a ssd and then create a partition and then a file system on the same
I want to delete existing partition on an ssd and then create a partition and then a file system on the same. How can I do it using a single command based on fdisk?
- 1
8
votes
3
answers
12k
views
Qemu TRIM and discard on a physical SSD device
I am running Windows 7 in a Qemu/KVM with a passed through GPU which I use for work-related stuff. I recently got fed up by it's unprecedented slowness due to it running off a mechanical drive, so I ...
- 91
2
votes
0
answers
623
views
Linux dm-crypt slowness with fast SSD
I'm experiencing slowness with an encrypted filesystem. Here are the details:
# /dev/sdd: TOSHIBA PX05SVQ192B AX02 /dev/sdd
# gdisk -l /dev/sdd
GPT fdisk (gdisk) version 0.7.1
Partition ...
2
votes
2
answers
856
views
How-To Chain Boot/Trampoline Boot into Ubuntu 17 on PCIe SSD without BIOS support
I have a server-grade SSD (Intel DC P3520) that will eventually end up in a server. Until the server is deployed in the data center I want to conduct some tests in a desktop machine.
I have an older ...
- 21
1
vote
1
answer
1k
views
iostat reports significantly different '%util' and 'await' for two identical disks in mdadm RAID1
I have a server running CentOS 6 with two Crucial M500 SSDs configured in mdadm RAID1. This server is also virtualized with Xen.
Recently, I started seeing iowait percentages creep up in the top -c ...
- 1,356
3
votes
1
answer
12k
views
How to extend CentOS 7 / partition after upgrading disk size on a VPS
We have a CentOS 7 VPS with 20GB of SSD space, we later upgraded it to 160GB but I'm a little confused on how to extend the / partition. We have multiple full backups but I'd rather not reinstalling ...
user430676
1
vote
1
answer
844
views
Intermittent I/O delays on part of RAID array causing poor MySQL performance
I am managing a bare-metal server running a MySQL database as well as some other software. We are seeing performance issues with some MySQL queries, but the issues occur intermittently, and almost ...
- 13
0
votes
0
answers
379
views
Optimize file system for Linux web server with SSD and HDD
I have just taken delivery of a new Centos 7 web server which comes with a 4Tb HDD and 240Gb SSD. Both are hardware RAID.
As it stands everything is installed on the SSD. I will need more than 240Gb ...
3
votes
0
answers
4k
views
fstrim vs. mount -o discard: How come discard.... doesn't?
I've noticed from time-to-time that running fstrim on mounted ext4 filesystems yields massive amounts of trimmed space even when these filesystems are mounted with the discard option. I thought the ...
- 3,714
1
vote
0
answers
67
views
SSD Temperture Increases during idle
I have 4 Samsung 850 EVO SSDs in a mdraid 10 array inside a high performance simple NAS. running Centos6.8 minimal. I have found that the SSD tempertures start to increase on their own without any ...
- 11
2
votes
1
answer
4k
views
hdparm unlock ssd with correct password encoding
I have an old password protected SSD connected via USB to my Linux System. I'm trying to unlock it with hdparm.
Problem is my password was ./perspective (it doesn't matter now because I only used it ...
- 121
0
votes
2
answers
4k
views
Mounting an SSD
I have recently got a 'dedicated GAME server' from OVH and I've been promised 2x480GB SOFT SSDs.
However, df -h shows this output:
root@dedi:/home/shavit# df -h
Filesystem Size Used Avail Use% ...
- 187
-1
votes
1
answer
104
views
SSD Server with trim enabled
I have a Windows Server (but I think this problem may apply to any UNIX server too) running using SSD. I have Kingston UV300 SSD and they allow TRIM. I also checked and my Windows is running with TRIM ...
- 308
7
votes
3
answers
9k
views
What is the performance impact of disabling NCQ?
Our cluster system runs currently under CentOS7 with SSDs and NCQ disabled. What kind of a performance drop is to be expected within an i/o-heavy usage scenario?
I'm not expecting a precise answer ...
- 81
0
votes
1
answer
72
views
Which bandwith can i expect, when i´m running a SATA SSD on a SAS interface?
So, i know this question had been asked before. I consider to buy a SSD for my Server, because i kinda hate the SAS HDDs in there.
I thought:
If i connect a SSD, which, in fact, handles way more ...
3
votes
1
answer
720
views
NVMe speed degradation after kernel upgrade
We are testing the speed of two Intel DC P3600 NVMe drives on a CentOS 7.1 system. They are configured in a software RAID1 using mdadm.
After upgrading the kernel from the (very old) 3.10 to the ...
- 173
2
votes
1
answer
2k
views
Force PCIe SSD to be /dev/sdb on linux install
Is there any options to force the PCIe SSD during install to be not /dev/sda? I was hoping to reserve the SSD to be limited to be only /var but the grub loader fails each time when I try to set the ...
- 543
0
votes
2
answers
1k
views
Recommended 3x SSD Raid for mysql database [duplicate]
I've been configuring dedicated MySQL server (linux) with 3x 300 GB SSD in SoftRaid. I'm trying to decide which Raid to use to get best performance. I'm expecting this database to be a read-heavy (90% ...
-1
votes
4
answers
712
views
load balance across several SSDs in a server
I would like to have a volume spanning several SSDs or HDDs in my server. When I write a file to this volume, the file is written in whole to one of those drives chosen randomly or in round robin ...
- 147
20
votes
2
answers
121k
views
How to unlock an SSD disk with hdparm?
I have an SSD disk with password protection, but the password was lost long time ago... so I tried to erase the ATA security with the hdparm command.
With "hdparm -I", the disk information ...
- 303
1
vote
3
answers
3k
views
Hard disk / SSDs - detection and handling of errors - is silent data corruption reliably prevented?
When an error occurs on a drive, is it correct to assume that it will always be detected and reported to the OS (if software RAID such as mdadm) or RAID controller (if hardware RAID) as a failed read (...
- 1,318
7
votes
1
answer
8k
views
How to send "ATA Secure Erase" command to SSD?
A very good way to erase a SSD which have SED support is to change the password/key. But what to do with those that doesn't have SED support?
This article says
Fortunately it is possible to erase ...
- 2,540
5
votes
2
answers
10k
views
Samsung 850 EVO + HP P410 limited iops?
I´m experiencing a weird write iops limitation with a HP P410 256mb cache controller and 4x consumer grade ssd´s (Samsung EVO 850) in RAID5/10. After upgrade to latest firmware (6.64) for HP P410 ...
- 63
10
votes
1
answer
7k
views
Poor iSCSI performance with SSD disks and 10 Gbe network
iSCSI Target
Ubuntu 14.04 (Trusty Tahr) with 16 GB RAM and 16 core CPU as LVM backed iSCSI target using three Samsung SSD disks, each capable of doing 65k IOPS using an LSI 6 Gbit/s ...
- 757
5
votes
1
answer
5k
views
How can I encrypt my SSD but still boot unattended (linux)? [closed]
I have a system that displays video from a camera feed with an overlay, and it must boot without any user intervention (the quicker the better). However, these systems will be in the hands of ...
- 151
2
votes
2
answers
226
views
Would software RAID0'ing SSDs help or hinder maximization of useful CPU work throughput?
My question is in the title... here is some background:
[OS is Linux.]
[UPDATE: The contents of this RAID0 is redundant (sync'd from SCM). I am not worried about the increased risk of data loss.]
...
- 133
2
votes
2
answers
2k
views
Running "find" command generates high load
I run this command on a Debian server with SSD drives configured as RAID 1:
ionice -c 3 find . -type f -amin -1440 -mmin +1441 -not -path custom/ -print0
on a path which contains over 1.7M files and ...
- 1,771
4
votes
1
answer
3k
views
Cannot remove mount option "discard" on an ext4 file system
I tried to turn off TRIM ("discard") on my ext4 filesystem, but I did not succeed.
I tried to add nodiscard option into /etc/fstab, but I can still see this:
# tune2fs -l /dev/md2 | grep ...
- 1,771