### Author:  [@pirboazo](https://discourse.nixos.org/u/pirboazo)
#### Post date: [July 17, 2019, 5:16pm UTC](https://discourse.nixos.org/t/nix-env-how-i-can-install-two-differents-versions-of-the-same-software-inside-a-user/3490/1 "2019-07-17T17:16:26Z")
Hello,
I want install in the same user two version of the software.
I think than specify the --profile directory was the solution.
but this command đ
nix-env -iA nixos.postgresql\_10 --profile ~/app/binary/
retrun: âš
error: â/home/postgres/app/binaryâ is not a symlink
So my question is :
How i can install two version of the software binary?
Why i want to do this ?
To use the pg\_upgrade binary to migrate db from one version to another.
Pierre
---
### Author:  [@Infinisil](https://discourse.nixos.org/u/Infinisil)
#### Post date: [July 17, 2019, 5:28pm UTC](https://discourse.nixos.org/t/nix-env-how-i-can-install-two-differents-versions-of-the-same-software-inside-a-user/3490/2 "2019-07-17T17:28:21Z")
It doesnât really make sense to install multiple versions of packages, because you canât have more than one version of a binary in your `PATH`.
I assume you intended to call `pg_upgrade` after installing like `~/app/binary/bin/pg_upgrade`? I recommend either calling the binary directly (which doesnât install anything):
```bash
$(nix-build --no-out-link '' -A postgresql_10)/bin/pg_upgrade
```
Or running the binary in a `nix-shell`, which also doesnât install anything:
```bash
nix-shell -p postgresql_10
[nix-shell:~]$ pg_upgrade
```
---
### Author:  [@lheckemann](https://discourse.nixos.org/u/lheckemann)
#### Post date: [July 17, 2019, 6:05pm UTC](https://discourse.nixos.org/t/nix-env-how-i-can-install-two-differents-versions-of-the-same-software-inside-a-user/3490/3 "2019-07-17T18:05:33Z")
For completenessâs sake: you can create another profile, but it mustnât already exist as a directory or file:
```auto
$ mkdir profile1
$ nix-env -p profile1 -iA nixos.hello
error: '/home/linus/profile1' is not a symlink
$ nix-env -p profile2 -iA nixos.hello
installing 'hello-2.10'
```
Note that this may not produce your desired behaviour though, for several reasons:
- It will not create garbage collection roots for the profile, meaning that its dependencies may be removed from under your feet during a garbage collection;
- It will keep historical versions of the profile right next to it. For example, the successful invocation of nix-env in my example created `profile2-1-link` in addition to `profile2`;
- The profileâs `bin` directory will not be in your `PATH`, nor will any other relevant environment variables be set, so you should have another use for putting them in a profile.
The first two issues can be solved by first creating a symlink to `/nix/var/nix/profiles/per-user/$USER/profilename`: `ln -s /nix/var/nix/profiles/per-user/$USER/testprofile profile3 && nix-env -p profile3 -iA nixos.hello`.
---
### Author:  [@pirboazo](https://discourse.nixos.org/u/pirboazo)
#### Post date: [July 17, 2019, 6:09pm UTC](https://discourse.nixos.org/t/nix-env-how-i-can-install-two-differents-versions-of-the-same-software-inside-a-user/3490/4 "2019-07-17T18:09:08Z")
Hi Infinisil đ thank for your reply.
I sorry , but the command pg\_upgrade have need of a path on the two versions.
pg\_upgrade -d oldCluster/data -D newCluster/data -b oldCluster/bin -B newCluster/bin
On Debian and all others distributions you can install several version.
You can have need to manage a cluster DB in 9.6 and one in 11.
Pierre
---
### Author:  [@pirboazo](https://discourse.nixos.org/u/pirboazo)
#### Post date: [July 17, 2019, 6:27pm UTC](https://discourse.nixos.org/t/nix-env-how-i-can-install-two-differents-versions-of-the-same-software-inside-a-user/3490/5 "2019-07-17T18:27:46Z")
Hi Linus,
In case of postgres database software, we donât install the same version.
We need to have the path on the oldversion and the newversion.
I search how resolve this problem inside nixos.
Nix-shell seem a way.
Thank.
Pierre
---
### Author:  [@pirboazo](https://discourse.nixos.org/u/pirboazo)
#### Post date: [July 17, 2019, 7:01pm UTC](https://discourse.nixos.org/t/nix-env-how-i-can-install-two-differents-versions-of-the-same-software-inside-a-user/3490/6 "2019-07-17T19:01:40Z")
Hi
Itâs OK
I install postgresql 10 default profile
i launch a nix-shell with -p postgresql\_11
and create a link .
ln -s /nix/store/88yxsbssvzrv22wymwy7m7ghpxy2fgnj-postgresql-11.4 pg11
after several step âŚ
launch the migrate from 10 to 11. đ
> ./app/binary/pg11/bin/pg\_upgrade -d ~/app/data/DB1 -D ~/app/data/DB2 -b /home/postgres/.nix-profile/bin -B ./app/binary/pg11/bin --link
> Performing Consistency Checks
* * *
Checking cluster versions ok
Checking database user is the install user ok
Checking database connection settings ok
Checking for prepared transactions ok
Checking for reg\* data types in user tables ok
Checking for contrib/isn with bigint-passing mismatch ok
Creating dump of global objects ok
Creating dump of database schemas
ok
Checking for presence of required libraries ok
Checking database user is the install user ok
Checking for prepared transactions ok
If pg\_upgrade fails after this point, you must re-initdb the
new cluster before continuing.
## Performing Upgrade
Analyzing all rows in the new cluster ok
Freezing all rows in the new cluster ok
Deleting files from new pg\_xact ok
Copying old pg\_xact to new server ok
Setting next transaction ID and epoch for new cluster ok
Deleting files from new pg\_multixact/offsets ok
Copying old pg\_multixact/offsets to new server ok
Deleting files from new pg\_multixact/members ok
Copying old pg\_multixact/members to new server ok
Setting next multixact ID and offset for new cluster ok
Resetting WAL archives ok
Setting frozenxid and minmxid counters in new cluster ok
Restoring global objects in the new cluster ok
Restoring database schemas in the new cluster
ok
Adding â.oldâ suffix to old global/pg\_control ok
If you want to start the old cluster, you will need to remove
the â.oldâ suffix from /home/postgres/app/data/DB1/global/pg\_control.old.
Because âlinkâ mode was used, the old cluster cannot be safely
started once the new cluster has been started.
Linking user relation files
ok
Setting next OID for new cluster ok
Sync data directory to disk ok
Creating script to analyze new cluster ok
Creating script to delete old cluster ok
## Upgrade Complete
Optimizer statistics are not transferred by pg\_upgrade so,
once you start the new server, consider running:
./analyze\_new\_cluster.sh
Running this script will delete the old clusterâs data files:
./delete\_old\_cluster.sh
Thank
Pierre
---
### Author:  [@lilyball](https://discourse.nixos.org/u/lilyball)
#### Post date: [July 17, 2019, 8:13pm UTC](https://discourse.nixos.org/t/nix-env-how-i-can-install-two-differents-versions-of-the-same-software-inside-a-user/3490/7 "2019-07-17T20:13:17Z")
If you want to run a binary from a given package itâs generally simpler to write this like `nix run nixpkgs.postgresql_10 -c pg_upgrade`.
---
### Author:  [@pirboazo](https://discourse.nixos.org/u/pirboazo)
#### Post date: [July 18, 2019, 1:08pm UTC](https://discourse.nixos.org/t/nix-env-how-i-can-install-two-differents-versions-of-the-same-software-inside-a-user/3490/8 "2019-07-18T13:08:25Z")
Hello lilyball,
Thank about your reply.
but the pg\_upgrade command need several args as you see below
> [@pirboazo](#):
>
> ./app/binary/pg11/bin/pg\_upgrade -d ~/app/data/DB1 -D ~/app/data/DB2 -b /home/postgres/.nix-profile/bin -B ./app/binary/pg11/bin --link
to bypass I created a symbolic link on the binary of the postgresql11 version.
But itâs not very clean.
Isnât it possible to create it with a nix command?
Pierre
---
### Author:  [@pirboazo](https://discourse.nixos.org/u/pirboazo)
#### Post date: [July 18, 2019, 3:05pm UTC](https://discourse.nixos.org/t/nix-env-how-i-can-install-two-differents-versions-of-the-same-software-inside-a-user/3490/9 "2019-07-18T15:05:32Z")
Hi all
Creating links like these is not a solution
because the next system cleanup will remove the packages in the /nix/store
How i can create profile on these links ?
Thank.
Pierre
---
### Author:  [@lilyball](https://discourse.nixos.org/u/lilyball)
#### Post date: [July 18, 2019, 6:30pm UTC](https://discourse.nixos.org/t/nix-env-how-i-can-install-two-differents-versions-of-the-same-software-inside-a-user/3490/10 "2019-07-18T18:30:18Z")
You can pass additional args to the `nix run` command. That said, the `-b /home/postgres/.nix-profile/bin` has me a little concerned, as `nix run` doesnât touch that symlink.
---
### Author:  [@danbst](https://discourse.nixos.org/u/danbst)
#### Post date: [July 18, 2019, 9:45pm UTC](https://discourse.nixos.org/t/nix-env-how-i-can-install-two-differents-versions-of-the-same-software-inside-a-user/3490/11 "2019-07-18T21:45:48Z")
You donât have to âinstallâ things:
```auto
$(nix-build '' -A postgresql_11)/bin/pg_upgrade --link \
-d ~/app/data/DB1 -D ~/app/data/DB2 \
-b $(nix-build '' -A postgresql_10)/bin \
-B $(nix-build '' -A postgresql_11)/bin
```
---
### Author:  [@lheckemann](https://discourse.nixos.org/u/lheckemann)
#### Post date: [July 19, 2019, 5:17am UTC](https://discourse.nixos.org/t/nix-env-how-i-can-install-two-differents-versions-of-the-same-software-inside-a-user/3490/12 "2019-07-19T05:17:04Z")
```auto
nix-build '' -A postgresql_11 -o pg11
nix-build '' -A postgresql_10 -o pg10
```
Will create symlinks to the packages which are also GC roots, i.e. their dependencies wonât get removed by the garbage collector until the symlinks themselves are removed (with the caveat that the âremoval detectionâ is fairly naĂŻve and will consider the symlink removed if it is moved/renamed as well).
---
### Author:  [@pirboazo](https://discourse.nixos.org/u/pirboazo)
#### Post date: [July 19, 2019, 9:48am UTC](https://discourse.nixos.org/t/nix-env-how-i-can-install-two-differents-versions-of-the-same-software-inside-a-user/3490/13 "2019-07-19T09:48:01Z")
Hi Linus,
Your solution work fine đđđ
Thank a lot.
Pierre