Data Domain: Cannot Delete Snapshot Softlocked by Replication Context
Summary: Found snapshot, created years ago, and still retained even though expired. Cannot be deleted because it is soft-locked
This article applies to
This article does not apply to
This article is not tied to any specific product.
Not all product versions are identified in this article.
Symptoms
- The snapshot created years ago, still retained although marked as expired already:
ddboost@dd02# snapshot list mtree /data/col1/avamar-1493130520 Snapshot Information for MTree: /data/col1/avamar-1493130520 ---------------------------------------------- Name Pre-Comp (GiB) Create Date Retain Until Status ----------------- -------------- ----------------- ----------------- ------- cp.20250309131143 213612.6 Mar 9 2025 07:13 Mar 10 2025 07:39 expired cp.20250309133359 214727.3 Mar 9 2025 07:34 Mar 10 2025 07:41 expired cp.20250310131141 207612.0 Mar 10 2025 07:13 cp.20250310133957 208726.9 Mar 10 2025 07:40 cp.20230919134341 403018.8 Sep 19 2023 07:44 Sep 20 2023 07:34 expired ----------------- -------------- ----------------- ----------------- -------
- Snapshot shown as soft locked in the log file ddfs.info
NOTE: The easiest way to capture that file would be to use scp to copy it from Data domain (DD) to another linux machine. Ensure to have the login credentials at hand to use this syntax:
admin@anylinuxmachine:~/>: scp dd_username@dd_hostname:/ddr/var/log/debug/ddfs.info .
admin@anylinuxmachine:~/>: grep "cp.20230919134341" ddfs.info
03/11 05:54:20.569 (tid 0x7fb71d0e6f10): rmsnapshot: mid=1583172823 s_name=cp.20230919134341.
03/11 05:54:20.569 (tid 0x7fb71d0e6f10): _dm_rmsnapshot: snapshot 'cp.20230919134341' is softlocked.
- The Data Domain alert was showing one alert related to one replication context out of sync:
ddboost@dd02# alerts show current Id Post Time Severity Class Object Message ------- ------------------------ -------- ----------- ------------------ ---------------------------------------------------------------- p0-924 Tue Nov 28 09:35:07 2023 CRITICAL Network Interface Index=11 EVT-NETM-00001: Network interface connectivity is down on ethMc. m0-1971 Mon Mar 10 06:56:36 2025 WARNING Replication context=1 EVT-REPL-00006: Sync-as-of time is more than 13109 hours ago. ------- ------------------------ -------- ----------- ------------------ ---------------------------------------------------------------- There are 2 active alerts.
- Listing the replication contexts in the Data Domain replication source is possible to get the details on that context #1.
- Replication context #1 have both source and destination referencing the mtree where the snapshot soft locked is contained.
avamar@dd02# replication show config CTX Source Destination Connection Host and Port --- ---------------------------------------------------------- ------------------------------------------------------------- ------------------------------------- 1 mtree://dd02.yourdomain.com.br/data/col1/avamar-1493130520 mtree://ddvault.yourdomain.com.br/data/col1/avamar-1493130520 ddvault.yourdomain.com.br (default) 2 mtree://dd02.yourdomain.com.br/data/col1/SysDR_ppmsv01 mtree://ddvault02.vault/data/col1/SysDR_ppmsv01 ddvault02.vault (default) 3 mtree://dd02.yourdomain.com.br/data/col1/SysDR_ppmsv01 mtree://ddvault02.vault/data/col1/SysDR_ppmsv01repl ddvault02.vault (default) 4 mtree://dd02.yourdomain.com.br/data/col1/SysDR_ppmsv02 mtree://dd03.yourdomain.com.br/data/col1/SysDR-R_ppmsv02 dd03.yourdomain.com.br (default) 5 mtree://dd02.yourdomain.com.br/data/col1/MtreeVault mtree://ddvault02.vault/data/col1/Mtreevaultdest ddvault02.vault (default) 6 mtree://dd02.yourdomain.com.br/data/col1/avamar-1493130520 mtree://ddvault02.vault/data/col1/avamar-1493130520dest ddvault02.vault (default) 7 mtree://dd02.yourdomain.com.br/data/col1/CritMtreeVault mtree://ddvault02.vault/data/col1/CritMtreeVaultDest ddvault02.vault (default) 8 mtree://dd02.yourdomain.com.br/data/col1/SysDR_ppmsv01 mtree://ddvault02.vault/data/col1/SysDR_ppmsv01dest ddvault02.vault (default) --- ---------------------------------------------------------- --------------------------------------------------------- ------------------------------------- DD System default Max-repl-streams per context: 32
NOTE: During troubleshooting, diagnosed destination host with the name ddvault.yourdomain.com.br, no longer exist. It was turned off and deleted.
Cause
- An old and no longer used replication context referencing the mtree where the snapshot exists, at the source Data Domain, was holding that soft lock.
- A Data Domain has been removed/deleted from the environment, but a replication context referencing that deleted Data Domain was not deleted, thus being left behind.
- A Data Domain has been removed/deleted from the environment, but a replication context referencing that deleted Data Domain was not deleted, thus being left behind.
Resolution
- We will need to break (is the process to delete that replication context), from the replication source Data Domain.
- Log in to the Data Domain and list the replication configuration to review and confirm the context to be break/deleted (on this example, context #1):
ddboost@dd02# replication show config CTX Source Destination Connection Host and Port --- ---------------------------------------------------------- ------------------------------------------------------------- ------------------------------------- 1 mtree://dd02.yourdomain.com.br/data/col1/avamar-1493130520 mtree://ddvault.yourdomain.com.br/data/col1/avamar-1493130520 ddvault.yourdomain.com.br (default) 2 mtree://dd02.yourdomain.com.br/data/col1/SysDR_ppmsv01 mtree://ddvault02.vault/data/col1/SysDR_ppmsv01 ddvault02.vault (default) 3 mtree://dd02.yourdomain.com.br/data/col1/SysDR_ppmsv01 mtree://ddvault02.vault/data/col1/SysDR_ppmsv01repl ddvault02.vault (default) 4 mtree://dd02.yourdomain.com.br/data/col1/SysDR_ppmsv02 mtree://dd03.yourdomain.com.br/data/col1/SysDR-R_ppmsv02 dd03.yourdomain.com.br (default) 5 mtree://dd02.yourdomain.com.br/data/col1/MtreeVault mtree://ddvault02.vault/data/col1/Mtreevaultdest ddvault02.vault (default) 6 mtree://dd02.yourdomain.com.br/data/col1/avamar-1493130520 mtree://ddvault02.vault/data/col1/avamar-1493130520dest ddvault02.vault (default) 7 mtree://dd02.yourdomain.com.br/data/col1/CritMtreeVault mtree://ddvault02.vault/data/col1/CritMtreeVaultDest ddvault02.vault (default) 8 mtree://dd02.yourdomain.com.br/data/col1/SysDR_ppmsv01 mtree://ddvault02.vault/data/col1/SysDR_ppmsv01dest ddvault02.vault (default) --- ---------------------------------------------------------- ------------------------------------------------------------- ------------------------------------- DD System default Max-repl-streams per context: 32
- Issue the command to break that replication context:
ddboost@dd02# replication break rctx://1
The 'replication break' command irrevocably turns off logical
replication from this mtree. To reconfigure the mtree
for replication, the destination mtree must not exist,
or, alternatively, 'replication resync' must be used.
Are you sure? (yes|no) [no]: yes
ok, proceeding.
ddboost@dd02#
NOTE: The message shown during the break execution is applied exclusively to the replication context being deleted. It does NOT impact the remaining replication contexts.
- List the replication configuration again to ensure the replication context #1 is gone:
ddboost@dd02# replication show config CTX Source Destination Connection Host and Port --- ---------------------------------------------------------- -------------------------------------------------------- ---------------------------------- 2 mtree://dd02.yourdomain.com.br/data/col1/SysDR_ppmsv01 mtree://ddvault02.vault/data/col1/SysDR_ppmsv01 ddvault02.vault (default) 3 mtree://dd02.yourdomain.com.br/data/col1/SysDR_ppmsv01 mtree://ddvault02.vault/data/col1/SysDR_ppmsv01repl ddvault02.vault (default) 4 mtree://dd02.yourdomain.com.br/data/col1/SysDR_ppmsv02 mtree://dd03.yourdomain.com.br/data/col1/SysDR-R_ppmsv02 dd03.yourdomain.com.br (default) 5 mtree://dd02.yourdomain.com.br/data/col1/MtreeVault mtree://ddvault02.vault/data/col1/Mtreevaultdest ddvault02.vault (default) 6 mtree://dd02.yourdomain.com.br/data/col1/avamar-1493130520 mtree://ddvault02.vault/data/col1/avamar-1493130520dest ddvault02.vault (default) 7 mtree://dd02.yourdomain.com.br/data/col1/CritMtreeVault mtree://ddvault02.vault/data/col1/CritMtreeVaultDest ddvault02.vault (default) 8 mtree://dd02.yourdomain.com.br/data/col1/SysDR_ppmsv01 mtree://ddvault02.vault/data/col1/SysDR_ppmsv01dest ddvault02.vault (default) --- ---------------------------------------------------------- -------------------------------------------------------- ---------------------------------- DD System default Max-repl-streams per context: 32
- Verify once the replication context #1 is deleted, that old snapshot is automatically marked as unexpired:
ddboost@dd02# snapshot list mtree /data/col1/avamar-1493130520 Snapshot Information for MTree: /data/col1/avamar-1493130520 ---------------------------------------------- Name Pre-Comp (GiB) Create Date Retain Until Status ----------------- -------------- ----------------- ----------------- ------- cp.20250317130903 214805.7 Mar 17 2025 07:10 Mar 18 2025 07:32 expired cp.20250317132705 215924.2 Mar 17 2025 07:28 Mar 18 2025 07:33 expired cp.20250318131055 215418.1 Mar 18 2025 07:12 cp.20250318133213 216537.6 Mar 18 2025 07:33 cp.20230919134341 403018.8 Sep 19 2023 07:44 Apr 8 2025 13:25 ----------------- -------------- ----------------- ----------------- -------
- Mark that snapshot as expired again:
ddboost@dd02# snapshot expire cp.20230919134341 mtree /data/col1/avamar-1493130520
Snapshot "cp.20230919134341" for mtree "/data/col1/avamar-1493130520" will be retained until Mar 18 2025 13:30.
ddboost@dd02# snapshot list mtree /data/col1/avamar-1493130520
Snapshot Information for MTree: /data/col1/avamar-1493130520
----------------------------------------------
Name Pre-Comp (GiB) Create Date Retain Until Status
----------------- -------------- ----------------- ----------------- -------
cp.20250318131055 215418.1 Mar 18 2025 07:12
cp.20250318133213 216537.6 Mar 18 2025 07:33
cp.20230919134341 403018.8 Sep 19 2023 07:44 Mar 18 2025 13:30 expired
----------------- -------------- ----------------- ----------------- -------
- Looking up for that snapshot in an updated copy of ddfs.info, the moment where the soft lock is removed, is captured:
admin@anylinuxmachine:~/>: grep cp.20230919134341 ddfs.info
03/18 13:25:16.663 (tid 0x7fb7969b2b40): updatesnapshot: mid=1583172823 m_name=avamar-1493130520 sid=35512 name=cp.20230919134341 retention is changed from 1741692419 to 1744140316 err :0
03/18 13:25:16.666 (tid 0x7fb7969b2b40): mrepl_snap_deref deref name=cp.20230919134341 (1583172823:35512) 1 -> 0
03/18 13:25:16.669 (tid 0x7fb7969b2b40): repl ctx 1: mrepl_protect_new_base deref'ing base cp.20230919134341 Not Referenced, USER
03/18 13:25:18.680 (tid 0x7fb7969b2b40): repl ctx: mrepl_snap_ref_cleanup Unsoftlocking snapshot name=cp.20230919134341 (1583172823:35512)
03/18 13:30:41.710 (tid 0x7fb7969b2b40): updatesnapshot: mid=1583172823 m_name=avamar-1493130520 sid=35512 name=cp.20230919134341 retention is changed from 1744140316 to 1742326241 err :0
03/18 13:30:41.710 (tid 0x7fb7969b2b40): FM fms_snapshot_update:1933 - Updated "cp.20230919134341", mtree "/data/col1/avamar-1493130520" 1742326241
03/18 13:32:50.061 (tid 0x7fb79ba174e0): rmsnapshot: mid=1583172823 s_name=cp.20230919134341.
03/18 13:32:50.076 (tid 0x7fb79ba174e0): rmsnapshot: done, mid=1583172823 m_name=avamar-1493130520 sid=35512 s_name=cp.20230919134341 retention=1742326241 ch=<dm_mtree:40000010000,1,0,400,6,0,e98eb815,440357a6,18045d05,d3463134,cadda83,9dfa4504:> cpg_id=1 cp_uuid=cf984be60de2e768:887b264e6a0bd7d6.
admin@anylinuxmachine:~/>:
- Start a new file system cleanup
ddboost@dd02# fi clean start Cleaning started. Use 'filesys clean watch' to monitor progress. ddboost@dd02# fi clean status Cleaning started at 2025/03/18 13:32:49: phase 1 of 6 (pre-merge) 0.0% complete, 25616 GiB free; time: phase 0:00:14, total 0:00:14
- Verify that the old snapshot is now gone, even though the cleanup is still in progress.
- The issue is resolved:
ddboost@dd02# snapshot list mtree /data/col1/avamar-1493130520 Snapshot Information for MTree: /data/col1/avamar-1493130520 ---------------------------------------------- Name Pre-Comp (GiB) Create Date Retain Until Status ----------------- -------------- ----------------- ----------------- ------ cp.20250318131055 215418.1 Mar 18 2025 07:12 cp.20250318133213 216537.6 Mar 18 2025 07:33 ----------------- -------------- ----------------- ----------------- ------
Affected Products
Data Domain Boost – File SystemArticle Properties
Article Number: 000296945
Article Type: Solution
Last Modified: 24 Mar 2025
Version: 1
Find answers to your questions from other Dell users
Support Services
Check if your device is covered by Support Services.