Topics created by 45lightrain

@45lightrain ok so lets start with some basics.

a 1GbE link (under theoretical conditions) is 1 Giga bits per second or 128MB/sec or 7.5GB/min raw data. Understand that there is ethernet overhead and you will never achieve 7.5GB/min.

So how is it possible to see speeds above 7.5GB/min on a 1GbE link? Simply data compression. So what you are seeing in the part clone screen is a composite speed including fog server speed sending the data to the network, network transfer time, the client receiving the image, expanding in it memory, and then writing it to disk.

If you are getting 5.5-6.1GB/min in partclone on a pure 1GbE network your fog environment is well designed and network well managed.

I wrote an article a few years ago that has some benchmark tools you can use to see where you can get additional speed out of your setup. https://forums.fogproject.org/topic/10459/can-you-make-fog-imaging-go-fast

So the executive summary is that if you want to go fast.

Install at least (1) 10GbE network link. (If you have many computers running the fog clients, run (2) 10GbE links in lag configuration. If you have many clients hitting your fog server while you are trying to image use a ssd disk or nvme drives on your fog server (I would look at spending here the last, typically its not the disk that is slow, unless you have just a single spindle hdd driving your fog server). Try to get the 10GbE network as close to the target computers as you can. If you are trying to image multiple target computers at the same time look into fog casting your image to the target computers. When capturing your image use the zstd compression tool over gzip. Set zstd at compression 11 to start. If your target computers have a lot of horsepower, 16GB of ram, and fast nvme disks you can get more data through your network by compressing the data more. This will put a heavier load on the target computer expanding the image and writing it to disk.

Think if your imaging as 3 factor triangle. You have server speed to get the image to the network adapter, the speed at which your network can move the image to the target computer, and finally the time it takes for the target computer to intake the image, expand it in memory and write to disk. In the imaging process the fog server typically has the least impact on imaging of the three.

@45lightrain said in Issues with capturing an image with a raid0 array.:

Also is fog able to capture both the OS SSD data and raid array data on the NVMe drives?

FOG captures disks in block mode. It doesn’t care about partitions (mostly). Also make sure that md0 is the true device for these drives. When you are in the FOS linux shell you can / should create a mount point and then mount /dev/mdX partition to see if you can read the content. I have seen where sometimes md0 is created but the real raid array is /dev/md126.

Also FOG calls a script before imaging starts. Sometimes its needed to assemble the array in this postinit script. Or do other things to prep the system for imaging. So the postinit script (found in the /images directory on the fog server) is a the place to put that code.

Also when you start in debug mode (when debugging the imaging process) you can actually start the imaging process from the command line by keying in fog. The imaging will stop at each debugPause; command in the imaging code as a breakpoint. If you notice something wrong, you can hit ctrl-C to exit back to the command prompt. To restart the imaging process again just rekey in fog.

While it doesn’t exactly apply here I wrote an article 8 years ago about imaging using the intel rst adapter that may contain a nugget of help: https://forums.fogproject.org/topic/7882/capture-deploy-to-target-computers-using-intel-rapid-storage-onboard-raid

@45lightrain Lets cover a few things that I’m aware of that might help you get to the bottom of the issue.

When you have a ProxyDHCP server and normal dhcp server on your network you will get two dhcp OFFERS. Well I guess it would be the same if you had two dhcp server you would see two offers, but that is a bit off point. You can tell if an OFFER packet is a proxy dhcp packet because dhcp option 60 will be set to PXEClient in the ProxyDHCP OFFER. That is a signal to the pxe booting client to come back and ask about pxe booting from the ProxyDHCP server. The pxe booting client will ignore the pxe boot information from the main dhcp server. A properly formed dhcp packet will have both the fields in the header {next-server} and {boot-file} filled out for the bootp booting protocol part of the protocol AND should have dhcp option 66 and 67 set for the dhcp booting protocol. Both must be filled out because its up to the pxe booting client to pick either the dhcp or bootp protocol. Your ltsp files are correct. The last one you posted has the dhcp-range… commented out, that turns off the proxydhcp feature in dnsmasq.

SO if you have a pihole server that runs dnsmasq, why are you running an external dnsmasq server. Does your pihole server have pxe boot options? I know pfsense has built in pxe boot fields you can fill out that supports dynamic (bios/uefi) boot loaders.

When trying to debug this wireshark/tcpdump is your friend that tells you what is flying down the wire. Just remember that dhcp is based on broadcast messages so you can “hear” them from any network port, and proxyDHCP like other unicast messages must be captured at the source, destination, or via a mirrored port.