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Server has SSD but showing ROTA 1
Hey guys!
Recently we have bought few servers to use in our rack in serverius DC
on of the server has 2 x Intel Xeon Gold CPU
4 x 3.84TB Intel S4510 SSD
It also has Hard RAID 10 using LSI 9361-4i and BBU
But the read and write speed of the server is very poor most of the time.
Even we have create few VPS on the server but VPS also showing poor read and write speed.
So we have check the following command to get ROTA result and it's showing ROTA 1
[root@vm01 ~]# cat /sys/block/sda/queue/rotational
1
[root@vm01 ~]# lsblk -d -o name,rota
NAME ROTA
sda 1
It should return 0 if it's SSD instead 1 right?
Today the DC confirm it has 4 x 3.84TB Intel S4510 SSD
They said maybe there some issue with RAID config, or OS install or Bios
We are checking but still not getting any result/issue till now.
So my question is there anyone who face same kind of situation?
Any suggestion?
Thank You!
Comments
Should be zero (0):
info from sysfs
cat /sys/block/sde/queue/rotational
1
You should get 1 for hard disks and 0 for a SSD.
lsblk
lsblk -d -o name,hctl,rota
NAME HCTL ROTA
sda 0:0:0:0 1
sdb 0:0:1:0 1
sdc 0:0:2:0 1
1 for hard disks and 0 for a SSD.
The datacentre probably is looking at different server, check the following command:
smartctl -a /dev/sda | grep Rotation
as it will tell you the hard drive is solid state device or hdd rpm speed.
Ok the issue of ROTA solve as we attached these disks with RAID controller that's why it's showing ROTA 1
But still don't know why the speed is poor.
Using RAID 10 so it must be increase more
official speed of these drives are
Sequential Read (up to) 560 MB/s
Sequential Write (up to) 510 MB/s
Random Read (100% Span) 97000 IOPS
Random Write (100% Span) 32000 IOPS
Latency - Read 36 µs
Latency - Write 37 µs
Power - Active 3.6W
Power - Idle 1.1W
And I am getting like this
Write Speed
sync; dd if=/dev/zero of=tempfile bs=1M count=1024; sync
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 1.67986 s, 639 MB/s
Read Speed (Maximum)
dd if=tempfile of=/dev/null bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 0.202361 s, 5.3 GB/s
It's true but DC said they have double checked and we have 4 SSD on it and everything matched what we have send to them
but our Admin said
It is true that SDA block rotational value should be 0 if it is a SSD drive; however, on this server the disks are not directly attached to the server. The disks are attached to the RAID controller and then this RAID controller projects make the array projects one to the operating system, so the SDA block rotation value will never be true in this case.
lsblk -d -o name,hctl,rota
NAME HCTL ROTA
sda 0:2:0:0 1
It's also showing ROTA 1
But DC confirm twice that we have 4 SSD present
sda is not the SSD. It’s your assembled raid array spit out to the system. You’re paying too much attention to whether something rotated or not, that’s unhealthy;-).
Issue is your raid controller. Adjust stuff there. Might need to change arrray config. Controller config. Or the controller all together if too slow cache:
What should be the expected speed?
I mean 639Mb/s write speed is too low for SSD RAID 10
That depends. You’ll need to re-search best practises on this controller before you find out.
I've seen everything. @Cyder just gave someone a mental health advice.
@ViridWeb
Listen to @Clouvider and have a closer look at your Raid controller as well as the driver.
Yes we are still checking the controller even the the BIOS as well..
Hope we can find the issue soon..
I wouldn't worry about the (system) BIOS. Look at the Raid controller and also at the drivers!
I'd start by updating the firmware of whatever you can. Proceed with making the RAID card as HBA/pass through mode and checking each drive individually.
Thanks for the suggestion but I have checked and firmware already up to date
But still it's not clear why I'm getting only 639Mb/s write speed on main server and only 179Mb/s on a VPS on it
Because I thik the speed should be more higher than that this because it's on SSD RAID 10
Even for both main server and vps on it
You're not going to get your issue resolved for yourself on a forum. You should really invest into some competent assistance, especially as it appears you're charging money for your services.
and
While I'd see and put it a bit less harsh @Clouvider is right. Main reason (and please don't take this personal. It's absolutely not): You are obviously clueless even to the point of not knowing what's relevant and how to measure.
For a start those are almost certainly two unrelated problems. One is about the controller, the other one is highly likely about how you configured your hypervisor/VPSs.
Focus on the controller first. Once it's OK you can concentrate on the hypervisor.
As for the controller your measurements (although not exactly sensible) suggest that your Raid controller is working more or less properly. Unfortunately the information you provide does not allow us to understand the details better. Please note that there are many and inter-related factors and parameters to look at and to properly configure.
And once more: also have a good look at the drivers. Usually there are quite some screws to turn and that can make a big difference.
May be try this :