| Hi folks, I’m trying setup a client that connect to a 500Gb ext4 disk on another machine running nbd server. Server: raspberry pi 3: uname -r 4.19.66+ Client: raspberry pi 3: uname -r 5.10.17-v7+ I’ve followed the information here [https://github.com/NetworkBlockDevice/nbd] and a lot of other sites $ sudo mount /dev/nbd2 /home/pi/Vols/nbd1-recipes/ mount: /home/pi/Vols/nbd1-recipes: can't read superblock on /dev/nbd2 Also it appears to be listening on default port - NOT ones specified in config file. This is how I’ve set up the server & client, it’s probably something obvious to more experienced folk. == rpi-C3 (192.168.1.14) server setup > sudo apt-get update > sudo apt-get install nbd-server > sudo nano /etc/nbd-server/config [generic] # If you want to run everything as root rather than the nbd user, you # may either say "root" in the two following lines, or remove them # altogether. Do not remove the [generic] section, however. user = nbd group = nbd includedir = /etc/nbd-server/conf.d allowlist = true # What follows are export definitions. You may create as much of them as # you want, but the section header has to be unique. [images] exportname = /home/pi/media/500G_FAITH/images port = 510029 [recipes] exportname = /home/pi/media/500G_FAITH/recipes port = 510030 [movie] exportname = /home/pi/media/500G_FAITH/movies port = 510031 > sudo modprobe nbd # NOT nbd-server! > lsmod | grep nbd nbd 40960 0 > sudo service nbd-server force-reload # if already running == client side > sudo apt-get install nbd-client > sudo modprobe nbd > nbd-client 192.168.1.14 -l Negotiation: .. images recipes movie > sudo nbd-client 192.168.1.14 -N recipes /dev/nbd2 Negotiation: ..size = 0MB Connected /dev/nbd2 > sudo nbd-client 192.168.1.14 -N movie /dev/nbd3 Negotiation: ..size = 0MB Connected /dev/nbd3 > sudo nbd-client 192.168.1.14 -N images /dev/nbd1 Negotiation: ..size = 0MB Connected /dev/nbd1 > dmesg | tail -n 10 [ 1417.883364] Buffer I/O error on dev nbd1, logical block 0, async page read [ 1417.884614] block nbd1: Other side returned error (22) [ 1417.884652] blk_update_request: I/O error, dev nbd1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 [ 1417.884673] Buffer I/O error on dev nbd1, logical block 0, async page read [ 1417.885977] block nbd1: Other side returned error (22) [ 1417.886016] blk_update_request: I/O error, dev nbd1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 [ 1417.886036] Buffer I/O error on dev nbd1, logical block 0, async page read [ 1417.887276] block nbd1: Other side returned error (22) [ 1417.888492] block nbd1: Other side returned error (22) [ 1417.889751] block nbd1: Other side returned error (22) > sudo nbd-client 192.168.1.14 -d /dev/nbd1 # thought it might be to do w/ nbd1 > sudo nbd-client 192.168.1.14 -N images /dev/nbd4 Negotiation: ..size = 0MB Connected /dev/nbd4 > dmesg | tail -n 10 [ 1848.831897] block nbd4: Other side returned error (22) [ 1848.833341] block nbd4: Other side returned error (22) [ 1848.834651] block nbd4: Other side returned error (22) [ 1848.836002] block nbd4: Other side returned error (22) > lsblk -f NAME FSTYPE LABEL UUID FSAVAIL FSUSE% MOUNTPOINT sda ├─sda1 vfat EFI 67E3-17ED └─sda2 hfsplus time_box_2018 f6427a3d-363b-3284-88c4-03ce3493aeff 115.5G 94% /media/pi/time_box_2018 nbd2 nbd3 nbd4 mmcblk0 ├─mmcblk0p1 vfat boot 5DE4-665C 203.4M 19% /boot └─mmcblk0p2 ext4 rootfs 7295bbc3-bbc2-4267-9fa0-099e10ef5bf0 4.1G 37% / > dmesg | tail -n 10 [ 1848.836002] block nbd4: Other side returned error (22) [ 1848.837430] block nbd4: Other side returned error (22) [ 1848.838860] block nbd4: Other side returned error (22) [ 1848.840224] block nbd4: Other side returned error (22) [ 1848.841691] block nbd4: Other side returned error (22) [ 1848.843077] block nbd4: Other side returned error (22) [ 1848.844415] block nbd4: Other side returned error (22) [ 2802.615037] block nbd3: Receive control failed (result -32) [ 2802.625871] block nbd2: Receive control failed (result -32) [ 2802.648444] block nbd4: Receive control failed (result -32) > ls /home/pi/Vols/ nbd1-recipes/ rpi-C2-nbd-500G/ tbx2018/ time_box_2018/ > sudo mount /dev/nbd2 /home/pi/Vols/nbd1-recipes/ mount: /home/pi/Vols/nbd1-recipes: can't read superblock on /dev/nbd2. > sudo parted -l Model: Seagate BUP Slim SL (scsi) Disk /dev/sda: 2000GB Sector size (logical/physical): 512B/512B Partition Table: gpt Disk Flags: Number Start End Size File system Name Flags 1 20.5kB 210MB 210MB fat32 EFI System Partition boot, esp 2 210MB 2000GB 2000GB hfs+ time_box_2018 Error: /dev/nbd3: unrecognised disk label Model: Unknown (unknown) Disk /dev/nbd3: 4096B Sector size (logical/physical): 512B/512B Partition Table: unknown Disk Flags: Error: /dev/nbd4: unrecognised disk label Model: Unknown (unknown) Disk /dev/nbd4: 4096B Sector size (logical/physical): 512B/512B Partition Table: unknown Disk Flags: Error: /dev/nbd2: unrecognised disk label Model: Unknown (unknown) Disk /dev/nbd2: 4096B Sector size (logical/physical): 512B/512B Partition Table: unknown Disk Flags: Model: SD SL08G (sd/mmc) Disk /dev/mmcblk0: 7948MB Sector size (logical/physical): 512B/512B Partition Table: msdos Disk Flags: Number Start End Size Type File system Flags 1 4194kB 273MB 268MB primary fat32 lba 2 273MB 7948MB 7676MB primary ext4 I’ve been trying to get them to talk for 2 days now One thing I did notice is that the port numbers in the config file don’t seem to change the fact it’s listening on he default port (10809)?? > sudo lsof -i -P -n | grep LISTEN COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME cnid_meta 312 root 3u IPv6 11170 0t0 TCP [::1]:4700 (LISTEN) afpd 324 root 3u IPv4 11195 0t0 TCP *:548 (LISTEN) sshd 426 root 3u IPv4 12126 0t0 TCP *:22 (LISTEN) sshd 426 root 4u IPv6 12128 0t0 TCP *:22 (LISTEN) dnsmasq 431 dnsmasq 5u IPv4 12046 0t0 TCP *:53 (LISTEN) dnsmasq 431 dnsmasq 7u IPv6 12048 0t0 TCP *:53 (LISTEN) nbd-serve 2026 nbd 3u IPv6 20100 0t0 TCP *:10809 (LISTEN) I’d be very grateful for any pointers, or other resources that my be of help. Thanks in advance, Simon |