Guillaume Filion's questions

I'm running a Debian 8 vm on Hyper-V (Win Srv 2012R2) and when I did a dist-upgrade of stable, I lost all network connectivity. Using the console, I was able to see the network interfaces as UP but could not ping any external address.

The dist-upgrade upgraded the kernel to linux-image-3.16.0-4-686-pae (3.16.7-ckt11-1+deb8u2).

I was able to work around this problem by adding 2 legacy network interfaces that are recognized with this new kernel, but I get a much reduced performance.

The Hyper-V modules seem to be loaded fine:

root@rproxy3:~# lsmod | fgrep hv_
hv_utils               17454  0
hv_netvsc              30069  0
hv_storvsc             17048  2
hv_vmbus               27978  6       hyperv_keyboard,hv_netvsc,hid_hyperv,hv_utils,hyperv_fb,hv_storvsc
scsi_mod              164132  5 sg,libata,sd_mod,sr_mod,hv_storvsc
root@rproxy3:~# dmesg | fgrep hv_
[    1.303529] hv_vmbus: Hyper-V Host Build:9200-6.2-16-0.16729; Vmbus version:2.4
[    1.336977] hv_vmbus: registering driver hv_storvsc
[    1.343214] hv_vmbus: registering driver hid_hyperv
[    1.344921] hv_vmbus: registering driver hv_netvsc
[    1.345790] hv_netvsc: hv_netvsc channel opened successfully
[    1.359193] hv_netvsc: hv_netvsc channel opened successfully
[    2.644921] hv_netvsc vmbus_0_13: Send section size: 6144, Section count:170
[    2.645032] hv_netvsc vmbus_0_13: Device MAC 00:15:5d:01:56:1c link state down
[    3.060851] hv_netvsc vmbus_0_11: Send section size: 6144, Section count:170
[    3.061034] hv_netvsc vmbus_0_11: Device MAC 00:15:5d:01:56:1b link state down
[    7.672833] hv_vmbus: registering driver hyperv_fb
[    7.893312] hv_vmbus: registering driver hyperv_keyboard
[    8.071484] hv_utils: Registering HyperV Utility Driver
[    8.071487] hv_vmbus: registering driver hv_util

but only the 2 legacy NICs are detected (I have 2 legacy and 2 synthetic NICs configured):

root@rproxy3:~# dmesg | fgrep eth
[    1.351882] net eth0: Digital DS21140 Tulip rev 32 at Port 0xe880, 00:15:5d:01:56:1e, IRQ 9
[    1.503780] net eth1: Digital DS21140 Tulip rev 32 at Port 0xec00, 00:15:5d:01:56:1f, IRQ 9
[   11.628988] net eth0: Using EEPROM-set media 100baseTx-FDX
[   11.733151] net eth1: Using EEPROM-set media 100baseTx-FDX

Any idea what to do to debug this further?

I'm trying to install Windows Server 2012R2 on a HP DL320 G6 with a Smart Array B110i SATA RAID Controller. During the install, it asks me to load the driver for the RAID, I load the drivers from cp022401 (also tried cp020545) and the machine promptly crashes with the HP BIOS frowny face.

That particular server was running Hyper-V 2012 with no problem, so I know that the hardware is fine, I'm just replacing the old hard drives with newer/bigger ones.

Do you have any idea how to install the B110i drivers successfully on Win2012R2?

I'm setting a firewall config for different distros/versions and I need to setup NOTRACK for DNS traffic.

On CentOS 7 (iptables v.1.4.21), I need to write like this:

-A PREROUTING -p udp -m udp --dport 53 -j CT --notrack

and on CentOS 6.5 (iptables v1.4.7), I need to write like this:

-A PREROUTING -p udp -m udp --dport 53 -j NOTRACK

I'd like to setup a script to test the iptables version and use the right syntax but I can't find which version changed it.

I'm setting up OpenBSD as a VM in HyperV 2012. It would be easier for me to just create one interface on the vm and have OpenBSD take care of setting up the vlans.

Is it possible to tell HyperV to send all traffic to a port whether it's tagged or not?

If I uncheck the "Enable virtual LAN identification" it looks like HyperV is only sending untagged traffic to the port.

I'm wondering if this is possible and if there's an implementation of this concept:

Imagine that I have a 1 GB RAM disk, a 1 TB internal hard drive and a 10 TB NAS on my LAN. Would it be possible to have a virtual drive that has 10 TB of space (stored on the NAS) but that keeps a local copy of the most accessed files on my internal HD and another copy of the files I'm currently using on the RAM disk?

It would be the same principle as virtual memory management but inverted: virtual memory copies the parts of the memory that are not in use to the slow device while this solution would copy the parts of the memory that are in use to the fast device.

I know that some enterprise SAN do this by mixing SSDs and HDs but I think that it could be done 100% in software.