SSD slows down on Xen Kernel

[floyd]

I know this is way off topic but hoping somebody has an answer.

I have an older Supermicro board that only has SATA 2 ports. I added a PCIe card to add SATA 3 ports and replaced the spinning drives with SSDs. I installed CentOS 7 and everything seems normal. I get the writes speeds I would expect.

Then I installed Virtualizor and the Xen kernel an now the drives are as slow as a spinning drive.

When I boot into the regular kernel everything is fine. Booting into the Xen kernel its all slow.

I have another server with Virtualizor and the OpenVZ 7 kernel and it works fine as well.

Something about the kernel is slowing the disk speed.

Does anybody have any ideas?

 

[floyd]

I think it may be a flaky card. Even when the speeds are good they quickly slow down after a few minutes.

 

[ikkeben]

I think it may be a flaky card. Even when the speeds are good they quickly slow down after a few minutes.

Board Supermicro has latest BIOS?, PCIe could also be a problem sometimes.
Sata3 board with own mem?

Raid? try some diferences there if so.But ok kernel and drivers for XEN could ofcourse be problem if not 100% supported by config. ( as always drivers could be , take therefore care latest firmwares and try different raids.

Such?

slow io performance on local disk on xenserver 6.5

discussions.citrix.com