All Questions
Tagged with performance hard-drive
223
questions
0
votes
1
answer
26
views
SAS channel speed and multiple disk setup
I have the following setup and looking for recommendations on the 2 connection options:
1x SAS Controller in HBA mode with 2x SAS Ports
2 SAS cables with 4 SAS connectors each
4x HDs with 6GB/s SAS ...
- 1
1
vote
2
answers
116
views
Prefetched Small File Cache
First, my use case: On my Linux-based server I am getting unsatisfactory disk IO performance for small files, and am limited to the approximately 100 IOPS that a 7200rpm HDD will support. This is of ...
- 13
1
vote
0
answers
382
views
Disk performance issues exclusively with RAID 10 (LVM RAID)
For some reason, I am suffering very poor disk performance on RAID 10, but normal performance on RAID 5.
For context, I have 4 x 1 TB hard drives in a server. They are the physical volumes within the ...
- 11
1
vote
1
answer
306
views
kafka cluster RAID vs JBOD with new hardware and kafka versions
we want to design production kafka cluster with 7 kafka machines , on RHEL OS
kafka version should be - 2.7
usually we are installing the kafka machine/s disks as RAID 10 ( as confluent recommended )
...
- 559
1
vote
0
answers
450
views
FIO test results wildly vary based on number of jobs
Take the following 3 commands:
fio --name=write_throughput --numjobs=8 \
--size=10G --time_based --runtime=60s --ramp_time=2s --ioengine=libaio \
--direct=1 --verify=0 --bs=1M --iodepth=64 --rw=write \...
- 273
0
votes
0
answers
3k
views
sdb: Disk read/write request responses are too high (read > 20 ms for 15m or write > 20 ms for 15m)
I use Zabbix agent to monitor my Linux servers.
I start to receive this alarm:
sdb: Disk read/write request responses are too high (read > 20 ms for 15m or write > 20 ms for 15m)
incident ...
- 1
0
votes
1
answer
1k
views
VMWare Disk Performance
I have an HP ProLiant DL380p Gen8 (VMWare 7u3 installed) with 2 pieces of 960GB SSD RAID1 arrays (total of ~1+1=2GB usage). The rest of the configuration is like
24 CPUs x Intel(R) Xeon(R) CPU E5-...
- 123
0
votes
1
answer
87
views
Disk read metrics not showing for postgres activity
I've long noticed that ESXI wasn't showing disk READ activity for my Ubuntu Postgres database server. I figured maybe it was just a weird bug with ESXI, as it would show disk WRITE activity.
I decided ...
- 99
0
votes
0
answers
1k
views
Hard resetting link, limiting SATA link speed to 1.5 Gbps from non-existent disk
Good morning!
Can anyone help me with a strange problem that I have in my Debian 8.8 Jessie server? I'm having these messages in my syslog:
[lun may 24 10:23:09 2021] ata9: limiting SATA link speed to ...
-1
votes
1
answer
427
views
Simulate some process IO with fio or other tool
Is there any way to track a specific process and get stats for disk IO such as queue depth, total reading/writing threads, percent of reads/writes and so on?
The main goal is to use all that ...
- 103
2
votes
0
answers
912
views
Openstack: VM disk I/O Tunning
In OpenStack, I am facing I/O performance issues. I am using virtio-scsi driver support in the quest. Currently, I am getting below mentioned performance.
WRITE: bw=37.2MiB/s (39.1MB/s), 37.2MiB/s-37....
- 21
0
votes
0
answers
826
views
Poor proxmox pveperf performance on a mdadm raid 1
When running pveperf on a Debian + Proxmox PowerEdge R540 server that uses two hard drive in a raid 1 configuration (using mdadm), I get very low performances in the number of FSYNCS/SECOND:
$ sudo ...
user537469
2
votes
1
answer
404
views
About IOPS of a RAID5 disk array without cache
we are using a 530-8i RAID adapter,which is none-cache supported, on a Lenovo ThinkSystem SR590 server.And we have 4 HDD(600GB/10K RPM/SAS) in the array.
I read an article about calculating the disk/...
- 21
1
vote
1
answer
410
views
Raw LVM disk write is four times faster on host than inside KVM guest?
I've got a Debian 10.6 Host, with a Debian 10.6 guest. KVM/Qemu/libvirt. The host has a software RAID 10 array with 6 mechanical disks. LVM is on top of the RAID array. One LV is passed into the guest ...
- 4,503
2
votes
0
answers
612
views
Access disk io data in linux without tools like iotop/iostat to find processes or files with IO
We have regularly high load average. With the help of a zabbix agent, I could narrow it down to be mainly because of cpu iowait (and lastly disk io). I am not allowed to install any additional ...
- 121
-1
votes
1
answer
3k
views
The causes for frozen server
We built one windows 2012R2 server (it has enough free memory/disk space, high performance of CPU), but it would be frozen for around half hour every 12 hours.
The symptoms:
couldn't access the ...
- 141
1
vote
0
answers
140
views
disk I/O latency spikes (contains log files from amplify)
Ubuntu 18.04 LTS server, disk is ssd. Application stack is: mongodb, node, nignx and some python.
Server is up 1 month and already had 3 OS disk fails where Ubuntu would go in read only mode. After ...
0
votes
0
answers
43
views
Linux software raid slow until reboot
I am running an debian 10 machine with 3 4tb hdd drives.
Each drive has a 1GB partition for a raid1 for the boot and the rest of the disk is configured as a raid 5 for lvm.
After a while of running I ...
- 101
6
votes
2
answers
2k
views
Why are concurrent downloads faster
Many download managers like this, this and this support downloading a file over multiple parallel connections, one per thread.
The concept is that each connection will download one part of the file ...
3
votes
1
answer
3k
views
Huge MFT and slow performance
I have a Windows Server 2012 R2 with huge MFT and slow performance when listing file in folder. Filesystem is about 350.000 files but in past many millions file was created and delete with crap Backup ...
- 61
1
vote
1
answer
285
views
Is my server drive on SATA2 or SATA3 based on this output?
smartctl output:
# smartctl -a /dev/sda | grep SATA
SATA Version is: SATA 3.1, 6.0 Gb/s (current: 3.0 Gb/s)
dmesg output (empty):
# dmesg | grep SATA
hdparm output:
# hdparm -I /dev/sda | grep ...
user555159
0
votes
1
answer
10k
views
Ceph hardware sizing calculator
I would like to calculate the Hardware sizing for a ceph cluster. There are so few references to the sizing, that I try to get these details here in the community.
E.g. what shall i have depending on
...
- 277
0
votes
1
answer
12k
views
What's the difference between 10k/15k SAS HDDs and SATA SSDs?
What is the rule of thumb in performance characteristics and differences between 10k / 15k revolutions per minute (RPM) Serial Attached Storage (SAS) hard disc drives (HDDs), versus Serial ATA (SATA) ...
- 14k
1
vote
1
answer
3k
views
Adding disks to existing RAID array
We want to increase disk space of one of our server. Currently it has 8 physical disks(4 x 480 GB, 4 x 1.9 TB) and 3 virtual disks(RAID 1 (2 x 480GB), RAID 1 (2 x 480 GB), RAID 10(4 x 1.9TB)). We want ...
- 111
5
votes
2
answers
1k
views
Server Hot Swap Hard Drives
We have a HP Proliant DL380 G9 server. We have a separate data drive which consists of 4 x 1TB 7.2k 6Gb hot-swappable SAS drives RAID 5'd to provide a 3GB logical drive. We've noticed the performance ...
David Colley
1
vote
1
answer
468
views
Extremely Low Random Read/Write Performance on (4096 Aligned) Advanced Format Disks
On a SATA 3.0, 6.0 Gb/s
*-disk:0
description: ATA Disk
product: WDC WD20EFRX-68E
vendor: Western Digital
physical id: 0
bus info: scsi@1:0.0.0
hw_sector_size: 512
...
- 1,875
0
votes
0
answers
186
views
partition ssd + hdd disk on ubuntu server running plesk
i have a new server with 256 SSD and 4TB SATA HDD, with the following logical volumes mounted
# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 1 223.4G 0 disk
├─sda1 ...
- 101
4
votes
1
answer
824
views
If I connect a SATA3 6Gbps SSD to a SAS2 6Gbps port using a breakout cable, will I get SATA3 speeds?
I have 2 SATA3 SSDs in my server, which are currently connected to SATA2 ports. If I wanted to get SATA3 speeds out of them instead, could I buy a SAS2 HBA and use an SFF-8087 to SATA breakout cable ...
- 43
0
votes
1
answer
274
views
Linux Ubuntu disk usage
Currently, I have a streaming dedicated server, below you will be able to see server details:
HDD: 12TB HDD
RAM: 64GB
Processor: Intel® Core™ i7-6700 Quad-Core Skylake Hyper-Threading
Network speed: ...
- 41
2
votes
2
answers
289
views
How to ask antivirus software to work slower and hence use less disk access?
It is our policy for our end-user's computers (usually laptops) to have high power CPUs, GPUs, RAMs (no less than 16GB) and HDD space (1TB), but we save money by choosing lower rotation speed of HDD. ...
- 111
0
votes
0
answers
99
views
Using hdparam for more strenuous tests
So I am tasked with getting some strenuous raw hard drive performance tests. We started with FIO but this has proven to be ineffective as the results are poor in windows and linux.
I tried Bonnie++ ...
- 217
3
votes
1
answer
2k
views
Intel NVME performance on Linux
I have an Intel 760P NVME drive hooked up to a Supermicro X11SRM-F with a Xeon W-2155 and 64GB of ddr4-2400 RAM. The specs for this drive claim 205K-265K IOPS (whatever 8GB span means) with about 3G/...
- 3,732
8
votes
2
answers
19k
views
what is the relation between block size and IO?
I have been reading about disk recently which led me to 3 different doubts. And I am not able to link them together. Three different terms I am confused with are block size, IO and Performance.
I ...
- 233
1
vote
4
answers
513
views
Why does disk latency drop during periods of heavy writes?
Looking at the output of Munin's diskstats plugin (which is reading from /proc/diskstats) I'm noticing what seems peculiar to me. The disk is a SSD, and I would assume, magnetic or solid state, that ...
- 11
3
votes
1
answer
988
views
Linux: how can I determine if an application is doing sequential or random disk I/O?
Everyone knows that databases tend to do lots of small random I/O while big data things like Kafka tend to do large sequential I/O, but if I'm approaching this as a sysadmin without making assumptions,...
- 2,655
0
votes
1
answer
771
views
Improving SQL speed - Can SSD and more RAM be effective?
I'm running a website on a VPS package on nomral Hard drive, and 3.25 GB RAM.
I created a test page and realized that by simply including an SQL command such as:
SELECT Name from table where Name IN ...
- 101
7
votes
3
answers
2k
views
3Gbps SSDs in RAID1 VS 6Gbps SAS Drives in RAID1 - Performance Difference?
I have bought two Intel DC S4500 480 SSDs (comes with 5 year warranty) to use with a HP G7 DL360 1U Server in RAID1. Unfortunately after purchasing the disks, I figured out that the integrated P410i ...
- 235
12
votes
2
answers
7k
views
Why is ZFS so much slower than ext4 and btrfs?
Problem
I recently installed a new disk and created a zpool on it:
/# zpool create morez /dev/sdb
After using it for a while, I noticed it was quite slow:
/morez# fio --name rw --rw rw --size 10G
...
- 1,503
9
votes
2
answers
8k
views
Why do sequential writes have better performance than random writes on SSDs?
An LBA (logical block addresses) is a mapping table implemented in the FTL to match between logical and physical pages/blocks in SSDs, my guess is that most SSDs (at least when they are empty) keeps ...
- 273
1
vote
1
answer
534
views
Constant unexplained disk activity
The screenshot below is from a Windows Server machine that is acting very strange lately. Every few minutes the HDD's go spinning like crazy without any reason I can explain.
RAM Checked, OK
HDD ...
- 123
2
votes
2
answers
2k
views
Why would diskspd perform better without cache?
We are currently investigating high disk latency on a Windows server 2012 r2 that run as an SQL server. It is a virtual machine under VMware and the datastore of the faulty disk is linked with a very ...
- 21
3
votes
0
answers
1k
views
ZFS slow read speed on 8 drive 4 vdev striped mirrors
I have 8 3TB WD Red SATA drives sdb through sdi i use in my pool.
My boot and OS drive is a an 850 EVO SSD on sda.
The 8 WD drives are on a Supermicro AOC-SAS2LP-MV8 Add-on Card, 8-Channel SAS/SATA ...
- 31
-3
votes
1
answer
55
views
Has my RAID drive failed?
I checked the output of my server today and it said:
root@s01 [~]# mdadm --detail /dev/md1
/dev/md1:
Version : 1.1
Creation Time : Sat Jul 7 18:23:24 2012
Raid Level : raid1
...
- 107
0
votes
0
answers
70
views
How to find which db/collection/query triggers disk read?
We're running a MongoDB 3.0 server with multiple users accessing it and we're experiencing very frequent disk reads by mongod process utilizing our SSD drives to 100%
During these peaks the page ...
- 221
6
votes
3
answers
5k
views
Massive performance degradation on sustained sequential write
I'm in the process of migrating data into LUKS partitions. Now that the operating system drive is running off LUKS, I tried to start migrating the data drives. Then the server stopped responding.
...
- 314
7
votes
3
answers
14k
views
SAS / SATA max number of connected disks vs performance
I would like to understand following things:
When I have a motherboard with SATA 6Gb/s and 8 ports, does it mean that every single port is able to provide 6Gb/s speed to disk that is connected over ...
- 324
2
votes
0
answers
40
views
Forking loads disk
I have a prefork/fork daemon. By atop I see, that master-process often consumes disk:
PID TID RDDSK WRDSK WCANCL DSK CMD
16830 - 7264K 48696K 18624K 10% our daemon
From strace I see, that it ...
- 41
4
votes
4
answers
7k
views
RAID 10 - many slow disks vs fewer fast disks
I am looking to buy HDDs for a single server which will be used as development server. The server will use ESXi as hypervisor and will have some but not too many virtual machines (web server, database ...
- 49
0
votes
0
answers
214
views
Mongodb, we can't go over 100 insert/sec on 200iops HDD
Thanks in advance for your help, we get a strange behaviour in mongodb. So we have a cluster of 20 shards, each composed of 1 master and 2 slaves. This database has a heavy load of write only. However ...
- 101
1
vote
1
answer
2k
views
Why my disk elevator is set to "deadline"
I have CentOS 6.x Linux server with kernel 2.6.32-573.8.1.el6.x86_64.
I did some checks today and I found that disk elevator is "deadline".
[root@srv ~]# cat /sys/block/sda/queue/scheduler
noop ...
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