From 95ad1961540709af6477e7c49860bc8792122fff Mon Sep 17 00:00:00 2001 From: caubet_m Date: Tue, 5 Aug 2025 17:13:11 +0200 Subject: [PATCH] Add MeG migration instructions --- pages/meg/99-support/migration-to-merlin7.md | 31 +++++++++++++++----- 1 file changed, 23 insertions(+), 8 deletions(-) diff --git a/pages/meg/99-support/migration-to-merlin7.md b/pages/meg/99-support/migration-to-merlin7.md index edb22fb..17f1d08 100644 --- a/pages/meg/99-support/migration-to-merlin7.md +++ b/pages/meg/99-support/migration-to-merlin7.md @@ -45,16 +45,16 @@ A `experiment_migration.setup` migration script must be executed from **any MeG #### When using the local `root` account - The script **must be executed after every reboot** of the destination nodes. -- **Reason:** On Merlin7, the home directory for the `root` user resides on ephemeral storage (no physical disk). +- **Reason:** On Merlin7, the home directory for the `root` user resides on ephemeral storage (no physical disk). After a reboot, this directory is cleaned, so **SSH keys need to be redeployed** before running the migration again. #### When using a PSI Active Directory (AD) account -- Applicable accounts include, for example: - - `gac-meg2_data` +- Applicable accounts include, for example: + - `gac-meg2_data` - `gac-meg2` - The script only needs to be executed **once**, provided that: - The home directory for the AD account is located on a shared storage area. - - This shared storage is accessible from the node executing the transfer. + - This shared storage is accessible from the node executing the transfer. - **Reason:** On Merlin7, these accounts have their home directories on persistent shared storage, so the SSH keys remain available across reboots. To run it: @@ -76,7 +76,7 @@ If you are stuck, email: [merlin-admins@lists.psi.ch](mailto:merlin-admins@lists ### Migration Procedure -1. **Run an initial sync** +1. **Run an initial sync**, ideally within a `tmux` session * This copies the bulk of the data from MeG to Merlin7. * **IMPORTANT: Do not modify the destination directories** * Please, before starting the transfer ensure that: @@ -142,9 +142,16 @@ Options: > Defaults can be updated if necessary. -#### Migration example +#### Migration examples -The following example migrates the entire online data +##### Example: Migrating the Entire `online` Directory + +The following example demonstrates how to migrate the **entire `online`** directory. + +{{site.data.alerts.tip}} +You may also choose to migrate only specific subdirectories if needed. +However, migrating full directories is generally simpler and less error-prone compared to handling multiple subdirectory migrations. +{{site.data.alerts.end}} ```bash [root@meg-s-001 bin]# experiment_migration.bash -b /meg -S /data/project/meg -S data1 -D data1 -p "online" @@ -158,7 +165,13 @@ Please confirm to start (y/N): N ❌ Transfer cancelled by user. ``` -The following example migrates a subdirectory: +##### Example: Migrating a Specific Subdirectory + +The following example demonstrates how to migrate **only a subdirectory**. + +⚠️ **Important:** +- When migrating a subdirectory, **do not** run concurrent migrations on its parent directories. +- For example, avoid running migrations with `-p "shared"` while simultaneously migrating `-p "shared/subprojects"`. ```bash [root@meg-s-001 bin]# experiment_migration.bash -b /meg -B /data/project/meg -S data1 -D data1 -p "shared/subprojects/meg1" @@ -170,3 +183,5 @@ The following example migrates a subdirectory: Please confirm to start (y/N): N ``` + +This command initiates the migration of the directory: `/meg/data1/shared/subprojects/meg1` → `login002.merlin7.psi.ch:/data/project/meg/data1/shared/subprojects/meg1`