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I need to add some temporary storage at my office but am running into issues with nbd-client blocking when accessing the device. I have very little equiment in that building so I have no real option of upgrading anything.
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Client and server are running the same 2.6.38 kernel and same nbd 3.13. <br>
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Server config:</div>
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[root@localhost]# cat /etc/nbd-server/config
<div>[generic]</div>
<div><span style="font-family: "Courier New", monospace;"># If you want to run everything as root rather than the nbd user, you</span></div>
<div><span style="font-family: "Courier New", monospace;"># may either say "root" in the two following lines, or remove them</span></div>
<div><span style="font-family: "Courier New", monospace;"># altogether. Do not remove the [generic] section, however.</span></div>
<div><span style="font-family: "Courier New", monospace;"> user = root</span></div>
<div><span style="font-family: "Courier New", monospace;"> group = root</span></div>
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<div><span style="font-family: "Courier New", monospace;"># What follows are export definitions. You may create as much of them as</span></div>
<div><span style="font-family: "Courier New", monospace;"># you want, but the section header has to be unique.</span></div>
<div><span style="font-family: "Courier New", monospace;">[nbd001]</span></div>
<div><span style="font-family: "Courier New", monospace;"> exportname = /mnt/nvdata/nbd/nbd001.nbd</span></div>
<div><span style="font-family: "Courier New", monospace;"> readonly = false</span></div>
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On the client:</div>
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<span style="font-family: "Courier New", monospace;">[root@localhost]# nbd-client -N "nbd001" 10.1.10.132 /dev/nbd0 -p</span>
<div><span style="font-family: "Courier New", monospace;">Negotiation: ..size = 2048MB</span></div>
<div><span style="font-family: "Courier New", monospace;">bs=1024, sz=2147483648 bytes</span></div>
<div><span style="font-family: "Courier New", monospace;">[root@localhost]# strace -e trace=file dd if=/dev/nbd0 of=/dev/null bs=1024 count=10</span></div>
<div><span style="font-family: "Courier New", monospace;">open("/dev/nbd0", O_RDONLY|O_LARGEFILE <---- Blocks forever here</span></div>
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<div>tcpdump shows the occasional packet, but no real stream of data.</div>
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<div>I do this at home all the time with the server running kernel 4.15.0 and nbd 3.16.2. The client at home is the same 2.6.38 with nbd 3.13.</div>
<div>I've already addressed the issue of max partitions being set to 0 on the clients by hard coding the value in the kernel driver. The 2.6.38 client is running nbd in the kernel and not a module.
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<div>I have a CentOS 5.2 machine there and tried to run it as a server too. Same result.
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<div>I've had a lot of success with nbd at home even on a Pi Zero W. I use it to mimic a Sandisk Cruzer on the OTG, but the "storage chip" of, of that Cruzer, is really /dev/nbd0. The Zero W loads a config file from my firewall at boot that tells it what
nbd image to connect to. It can be slow at times, but it has eliminated a tack of USB 2.0 sticks I had on my desk. I can also use dd on my server to create another "stick" instead of running to Wal-Mart when I need one.</div>
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