Search Results for: nbd loopback

nbdkit for loopback pt 7: a slow disk

What happens to filesystems and programs when the disk is slow? You can test this using nbdkit and the delay filter. This command creates a 4G virtual disk in memory and injects a 2 second delay into every read operation: … Continue reading

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nbdkit for loopback pt 6: giant file-backed disks for testing

In part 1 and part 5 of this series I created some giant disks with a virtual size of 263-1 bytes (8 exabytes). However these were stored in memory using nbdkit-memory-plugin so you could never allocate more space in these … Continue reading

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nbdkit for loopback pt 5: 8 exabyte btrfs filesystem

Thanks Chris Murphy for noting that btrfs can create and mount 8 EB (approx 263 byte) filesystems effortlessly: $ nbdkit -fv memory size=$(( 2**63-1 )) # modprobe nbd # nbd-client -b 512 localhost /dev/nbd0 # blockdev –getss /dev/nbd0 512 # … Continue reading

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nbdkit for loopback pt 4: loopback-mounting compressed images

nbdkit is a pluggable NBD server with lots of plugins and filters. Two of the plugins[1] handle compressed files (for gzip and xz respectively). We can uncompress and serve a file on the fly. For gzip it’s kind of inefficient. … Continue reading

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nbdkit for loopback pt 3: loopback mounting VMware disks

nbdkit is a pluggable NBD server and it comes with a very wide range of plugins (of course you can also write your own). One of them is the VMware VDDK plugin, an interface between nbdkit and the very proprietary … Continue reading

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nbdkit for loopback pt 2: injecting errors

nbdkit is a pluggable NBD server with a filter system that you can layer over plugins to transform block devices. One of the filters is the error filter which lets you inject errors. We can use this to find out … Continue reading

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nbdkit as a flexible alternative to loopback mounts

Look: $ nbdkit -f -v memory size=$(( 2**63-1 )) On the same machine: # modprobe nbd # nbd-client localhost /dev/nbd0 Warning: the oldstyle protocol is no longer supported. This method now uses the newstyle protocol with a default export Negotiation: … Continue reading

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nbdkit / FOSDEM test presentation about better loop mounts for Linux

I’ve submitted a talk about nbdkit, our flexible pluggable NBD server, to FOSDEM next February. This is going to be about using NBD as a better way to do loop mounts in Linux. In preparation I gave a very early … Continue reading

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nbdkit + xz + curl

I’ve submitted a talk about nbdkit, our flexible, pluggable NBD server, to FOSDEM next year about how you can use nbdkit as a replacement for loopback mounts (or “loop mounts” as I was told off for not calling them last … Continue reading

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NBD graphical viewer

Ever wondered what is really happening when you write to a disk? What blocks the filesystem writes to and so on? With our flexible, plug-in based NBD server called nbdkit and a little Tcl/Tk program I wrote you can now … Continue reading

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