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Raid 10 SSD I/O Performance Issue !
Hi
I rented a server , with 4x512GB SSD and did raid 10 .
So I did raid 1 in root directory and raid10 in /home directory .
I am getting only 121 MB/s (Raid1) I/O in root directory and 219 MB/s IO in /home directory (Raid10) , all most same as SATA Drives
The Drives are Samsung 850 Pro .
But on my other servers (SSD) , I do get 600MB/s-950MB/s or even 1.2GB/s IO on Raid 10 .
So , what do you think of this server IO performance ?
ThankYou
RIYAD
Comments
Could be aliens. Or many other reasons, hard to judge by the info you provided.
what kind of more information I can add to the post, to make things a bit clear ?
What kind of system is it?
What motherboard?
Does it have SATA3 ports?
Does the SATA layer report that the links to the SSDs are running at 6Gbps or 3Gbps speeds?
Are the partitions you used to create the RAID properly aligned to 4K?
Are the RAIDs synced, or are they syncing at the moment?
What else is going on on the system while you are testing it?
What is the performance of the individual SSDs, without RAID?
What does SMART report about the SSDs?
What are you using to test the IO speeds?
What kind of system is it?
What motherboard?
Does it have SATA3 ports?
Does the SATA layer report that the links to the SSDs are running at 6Gbps or 3Gbps speeds?
ata2: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
ata3: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
ata4: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
Are the partitions you used to create the RAID properly aligned to 4K?
Are the RAIDs synced, or are they syncing at the moment?
What else is going on on the system while you are testing it?
What is the performance of the individual SSDs, without RAID? What does SMART report about the SSDs?
What are you using to test the IO speeds?
Could not test disk individually with out raid ,
i had the same problems 3 weeks ago and the sata controller had a issue and work only in 3gps
This is a problem, this will slow everything down. Try rebooting / power cycling and see if the problem clears. Also check this SSD's SMART status. Could be a SSD problem or SATA cable problem.
please use the command fdisk -u -l /dev/sda
(and the same for the other SSDs)
Also why is your /dev/sdd using different partitioning scheme than the rest?
Here is the out put of fdisk -u -l /dev/sda
not sure , why the partitioning like that , the partition was done by the Server Company
I did reboot , still showing ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 310)
I will power off the server and start again , and see the result
Again , Thank you very much @rds100 for helping
Or, these partitions look properly aligned (at 8 sectors / 4K boundary). Check if the other disks are the same. Also i would repartition /dev/sdd to make it like the rest.
Here the other disk , seems different
By other disk i mean sdb sdc and sdd. sda1 sda2 and sda3 are not "disks".
right disks !
http://pastebin.com/p8XJMtKa
sdb and sdc look OK. I would get rid of the GPT on sdd and repartition it like the others.
ok , will do that , and see if the performance , improves .
It turns out that the SATA data and/or power cable connected to /dev/sdd (SATA-0) was defective, this caused the drive out put at 1.5 Gbps.
The server company has replaced it , how getting 400MB/s IO
Thank you @rds100
@rds100 Good Stuff