High IO delay

Bigmat

New Member
Nov 16, 2023
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Hi,

I have a trouble with my R710 server. I got 2x Intel X5670 CPUs, 192 GO ram, H700 raid controller. I have currently 1 ssd for proxmox OS and 8 ssds for VM storage. I buy this server for testing purpose, I just need performance and a lot of storage. So my 8 storages SSD is Samsung EVO 870, configured in raid 0 (that give me near 4TO). Proxmox runs in 8.0.4. Firmwares have been updated 1 year ago.

But I have a trouble that the only solution is to reboot server...

1: I cant connect to any VM with noVNC. I got "error: Failed to run vncProxy.
2: the VM is extra slow or I cant connect with RDP. SSH seems ok, but very slow.
3: the io delay run about 25-35%.

1700156695775.png

pveperf
CPU BOGOMIPS: 140454.00
REGEX/SECOND: 2131482
HD SIZE: 36.81 GB (/dev/mapper/pve-root)
BUFFERED READS: 226.58 MB/sec
AVERAGE SEEK TIME: 0.33 ms
FSYNCS/SECOND: 1475.88
DNS EXT: 40.85 ms
DNS INT: 22.82 ms (local)



Is the FSYNCS/Second is normal?


I suspect a disk is failing, but what do you think about it? May is better to reset my HW controller to Raid5 ?


Thanks.

Mathieu
 
My storage is not configured in ZFS and disks are managed by hardware.

1700161786292.png

I know that ZFS wear out consummer disk fastly. This is not the case here.

Mathieu
 
I know that ZFS wear out consummer disk fastly. This is not the case here.
Yes, but the SSDs are still rubish and that's the point. It's like buying a Ferrari and putting in a lawn mower motor as you did with those SSDs. That is exactly the point I was refering to and this forum is getting overwhelmed with threads like this....


Is the FSYNCS/Second is normal?
Please run pveperf on your SSDs. If not run with any argument, it'll benchmark your root disk (as shown in the output). You need to run it on your SSD LVM group, maybe creating a volume and a filesystem first.
 
consumer drives behind hw raid controller is not recommended.
hw raid controller disable disks cache, so without cache with bbu on the hw raid controller, perfs are really bad, like a regular hdd.
 
Ok.

Kingston DC600M is a good choice? Or have you some recommandation for a good disk choice?

Thanks for your help.
Mathieu
 
im using Intel s3610 Sata SSDs (older model, but can be had cheap) and have absolutely zero problems.
im using the 1.6TB model which has very good write endurance and my pveperf says this about it (zfs mirror):

Code:
FSYNCS/SECOND:     6488.14

thats a lot faster than your kingston drive or the samsung evos and the write endurance is worlds apart (10.7PBW vs 0.3PBW, so ~30 times more write endurance).

here is a link to the specific drives im using. im usually buying them cheap on aliexpress:

https://www.aliexpress.com/item/1005004979930308.html

i bought 2 drives so far and both were brand new without any power on hours and no data written (the smart output was clean).
 
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