[SOLVED] Very poor disk speed with HP DL380 GEN9 (40mb/s write speed)

sinan

New Member
Jul 31, 2021
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Hi all,

I'm having an issue with HP DL380 GEN9 Server
2 x Xeon 2660 CPU with 128GB Memory, Smart Array P440 Raid Controller, 2 x 1TB Kingston DC450R Series Enterprise SSD (560mb/s read, 510 write), Raid 1 Over P440

The problem is very poor disk performance...
Installed Windows Server 2K22 on VM and getting very slow transfer rate while writing data and its using almost %30 of cpu while copy process.
I tested with CrystalDiskMark and results are; 300mb/s seq1m. read and 50mb/s seq1m. write speed

I tested with all cache options under VM's Hardware->Hard Disk scsi0 (Direct Sync, Write through, Write Back and No cache) Getting 150mb/s write speed with "Write through" option but almost freezes the vm after 1 min. and slow down vm completely.

Removed P440 Raid Controller and tried with builtin B140 Controller with Single Disk (without raid), result is same...
Disabled B140 Raid controller and installed with AHCI mode on single disk, result is same.
I even attached second disk as directory and started backup Vm's image within proxmox to second SSD, result is same (around 30-50mb/s backup speed) So i think problem isn't releated with the VM configuration.

and i test VM's hardware with 2 sockets and 20 cores, 1 socket and 10 core, even 1 socket 4 core with 16gig memory. Result is same again.
Turned swap off and result is same.

And as a result, I couldn't go a barley length
Thanks in advance for your brillant ideas and advice
 
While those SSDs are marketed as enterprise SSD, they still lack the powerloss protection. So sync write performance will never be great, as sync writes can't be cached in the SSDs RAM cache.
 
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disk writecache is disabled by default in hp bios, because smart array has a bbu and even on embedded sata to ensure reliability imo. try with a pcie sata controller.
i use dc500r/m which has PLP.
 
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disk writecache is disabled by default in hp bios, because smart array has a bbu and even on embedded sata to ensure reliability imo. try with a pcie sata controller.
i use dc500r/m which has PLP.
You're right, everything is perfect when i enabled write cache on P440 controller with Raid 1. I'm getting around 500Mb/s write speed. My raid battery status showns as "healthy", but i'm not sure to keep enabled write cache is ON.
I will protect the system with online UPS, so do you think is there any risk with Write Caching enable option in this situation ?
 

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