wok-current annotate nbd/description.txt @ rev 24992
Up sip (4.19.25)
| author | Pascal Bellard <pascal.bellard@slitaz.org> |
|---|---|
| date | Sat May 14 18:19:29 2022 +0000 (2022-05-14) |
| parents | |
| children |
| rev | line source |
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| Hans-G?nter@24958 | 1 With this compiled into your kernel, Linux can use a remote server |
| Hans-G?nter@24958 | 2 as one of its block devices. |
| Hans-G?nter@24958 | 3 Every time the client computer wants to read /dev/nbd0, it will send |
| Hans-G?nter@24958 | 4 a request to the server via TCP, which will reply with the data |
| Hans-G?nter@24958 | 5 requested. |
| Hans-G?nter@24958 | 6 This can be used for stations with low disk space (or even diskless |
| Hans-G?nter@24958 | 7 - if you use an initrd) to borrow disk space from other computers. |
| Hans-G?nter@24958 | 8 Unlike NFS, it is possible to put any file system on it. |
| Hans-G?nter@24958 | 9 But (also unlike NFS), if someone has mounted NBD read and write, |
| Hans-G?nter@24958 | 10 you must assure that no one else will have it mounted. |
| Hans-G?nter@24958 | 11 |
| Hans-G?nter@24958 | 12 Current state: |
| Hans-G?nter@24958 | 13 It currently works. Network block device is pretty stable. |
| Hans-G?nter@24958 | 14 It was originaly thought that it is impossible to swap over TCP; |
| Hans-G?nter@24958 | 15 this turned out not to be true. |
| Hans-G?nter@24958 | 16 However, to avoid deadlocks, you will need at least Linux 3.6. |
| Hans-G?nter@24958 | 17 |
| Hans-G?nter@24958 | 18 It is possible to use NBD as the block device counterpart of FUSE, |
| Hans-G?nter@24958 | 19 to implement the block device's reads and writes in user space. |
| Hans-G?nter@24958 | 20 To make this easer, recent versions of NBD (3.10 and above) |
| Hans-G?nter@24958 | 21 implement NBD over a Unix Domain Socket, too. |