Nix Installation Guide: Difference between revisions

Line 11:

After that being done, you can use all Nix commands as a normal user without any special permissions (for example by using <code>sudo</code>).

== Nix store on an unusual filesystem ==

=== Case insensitive filesystem on Linux ===

Most Linux filesystems are case sensitive. If your nix store is on a case sensitive filesystem like CIFS on Linux, derivation outputs cannot contain two files differing only in case in the same directory. Nix can work around this by adding <code>use-case-hack = true</code> to your nix configuration (<code>/etc/nix/nix.conf</code> for a multi-user-install or <code>~/.config/nix/nix.conf</code> otherwise). Unfortunately, this will change the hash of some derivations and thus make the binary cache useless.

=== NFS ===

Without special care, concurrent use of Nix if the nix store is on a NFS filesystem may corrupt Nix's sqlite database.

To prevent this, add <code>use-sqlite-wal = false</code> to your nix configuration and recompile nix with this patch:

--- a/src/libstore/sqlite.cc

+++ b/src/libstore/sqlite.cc

@@ -28,7 +28,7 @@ namespace nix {

SQLite::SQLite(const Path & path)

{

if (sqlite3_open_v2(path.c_str(), &db,

- SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0) != SQLITE_OK)

+ SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, "unix-dotfile") != SQLITE_OK)

throw Error(format("cannot open SQLite database '%s'") % path);

}</syntaxHighlight>

(source: [https://github.com/NixOS/nix/issues/2357 this issue])

Nix is hard to build by hand, but you can still use vanilla nix without concurrent use, so you can install nix with a NFS store as follows:

* Install nix with the vanilla binary installer

* Create a file <code>nfs-nix.nix</code>:

with import <nixpkgs> {};

nix.overrideAttrs (old: {

patches = (old.patch or []) ++ [ ./nfs.patch ];

# if you are in a hurry

doInstallCheck = false;

})

</syntaxHighlight>

* Run <code>nix-env -if ./nfs-nix.nix</code>

* From then on, you can use nix concurrently without risk of corrupting the sqlite database.

== Installing without root permissions ==

@@ Line 11: / Line 11: @@
 After that being done, you can use all Nix commands as a normal user without any special permissions (for example by using <code>sudo</code>).
+== Nix store on an unusual filesystem ==
+=== Case insensitive filesystem on Linux ===
+Most Linux filesystems are case sensitive. If your nix store is on a case sensitive filesystem like CIFS on Linux, derivation outputs cannot contain two files differing only in case in the same directory. Nix can work around this by adding <code>use-case-hack = true</code> to your nix configuration (<code>/etc/nix/nix.conf</code> for a multi-user-install or <code>~/.config/nix/nix.conf</code> otherwise). Unfortunately, this will change the hash of some derivations and thus make the binary cache useless.
+=== NFS ===
+Without special care, concurrent use of Nix if the nix store is on a NFS filesystem may corrupt Nix's sqlite database.
+To prevent this, add <code>use-sqlite-wal = false</code> to your nix configuration and recompile nix with this patch:
+<syntaxHighlight lang="diff">
+--- a/src/libstore/sqlite.cc
++++ b/src/libstore/sqlite.cc
+@@ -28,7 +28,7 @@ namespace nix {
+ SQLite::SQLite(const Path & path)
+ {
+     if (sqlite3_open_v2(path.c_str(), &db,
+-            SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0) != SQLITE_OK)
++            SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, "unix-dotfile") != SQLITE_OK)
+         throw Error(format("cannot open SQLite database '%s'") % path);
+ }</syntaxHighlight>
+(source: [https://github.com/NixOS/nix/issues/2357 this issue])
+Nix is hard to build by hand, but you can still use vanilla nix without concurrent use, so you can install nix with a NFS store as follows:
+* Install nix with the vanilla binary installer
+* Create a file <code>nfs-nix.nix</code>:
+<syntaxHighlight lang="nix">
+with import <nixpkgs> {};
+nix.overrideAttrs (old: {
+patches = (old.patch or []) ++ [ ./nfs.patch ];
+# if you are in a hurry
+doInstallCheck = false;
+})
+</syntaxHighlight>
+* Run <code>nix-env -if ./nfs-nix.nix</code>
+* From then on, you can use nix concurrently without risk of corrupting the sqlite database.
 == Installing without root permissions ==