Forwarded to devs Backup problem : incremental backup doesn't work and backup use all the swap

[LaurentR2D2]

TITLE:

Backup problem : incremental backup doesn't work and backup use all the swap​

PRODUCT, VERSION, OPERATING SYSTEM, ARCHITECTURE:

CPU Intel(R) Xeon(R) CPU X3450 @ 2.67GHz (8 core(s))
Version Plesk Obsidian v18.0.21_build1800191128.17 os_CentOS 7
OS CentOS Linux 7.7.1908 (Core)
RAM : 8 Gb
SWAP : 1 Gb​

PROBLEM DESCRIPTION:

Scheduled backup is set for daily backup with full backup once a week and incremental backup activated. Instead of that, I get a full backup everyday(43 Gb backup every day). I also get swap usage alarms during the time backup is working. I've just migrated my Plesk install and the scheduled backup is the same than on the previous machine which was less strong and on which backup was working fine (43 Gb backup once a week and around 300 Mb incremental backups the other days). The machine was :

1x Intel® C2350 (Avoton)
RAM : 4 Gb DDR3 ECC
SWAP : 1 Gb
Plesk Obsidian​

STEPS TO REPRODUCE:

Activate a scheduled backup this way :

ACTUAL RESULT:

Full backup of 43 Gb every day and high usage of the swap. The highest values on the screenshot are between 01:00 and 01:30 am.

EXPECTED RESULT:

Full backup of 43 Gb once a week and incremental backup of around 300 Mb each day and no swap usage alarm when backup is working.​

ANY ADDITIONAL INFORMATION:

​

YOUR EXPECTATIONS FROM PLESK SERVICE TEAM:

Confirm bug​

 

[Bitpalast]

Same issue here on a fresh original Obsidian installation.

 

[Aytalina]

Hello LaurentR2D2 and Peter Debik,

Thank you for your reports.

As for the issue with performance, it has been already solved in the scope of PPP-46617. Please wait for the next release of Plesk 18.0.22 and let us know if the issue persists.

Regarding scheduled incremental backups, I need some additional information from you.

Could you please send us your backup logs of the next backup execution (In DM). Their location is specified at Backup Logs.

Please make sure that debug mode was enabled either in Plesk How to enable / disable Plesk debug mode (P.4 without logging of SQL queries and stdin and stdout for external utilities calls) and Plesk Backup How to enable debug mode for Plesk backup operations (Please refer to Additional debug logging using pmmcli-rc utility section).

(If it was enabled, you could send the logs of the latest backup execution).

I am looking forward to hearing from you soon.

Thank you,
Aytalina

 

[Bitpalast]

I have sent you the logs as a zip file in a private message.

 

[LaurentR2D2]

I've enabled the debug mode as you have told, and I've reactivated the Sheduled backup. I had disabled it because of the problems. Perhaps I should wait for at least two backups now since it has been disabled yesterday, so hasn't work today ? I still have 12-08 and 12-09 in the backup manager window.

 

[LaurentR2D2]

I send you the log file in private message finally. I don't know what has happened, but Plesk has made an incremental backup this time, and I haven't received any swap usage alarm. The Plesk version hasn't changed :
Version Plesk Obsidian v18.0.21_build1800191128.17 os_CentOS 7

 

[Aytalina]

@Peter Debik and @LaurentR2D2,

We do not see anything suspicious in the logs you have provided and, as LaurentR2D2 mentioned, an incremental backup was created successfully.

Question: was your first scheduled backup created on the empty server, i.e. without subscriptions?

 

[LaurentR2D2]

Here is what I've done :

1) I've installed Plesk on my new server without adding any subscription, .... I have installed some extensions, to get the same ones than on my previous server, that's all. The scheduled backup must be part of the install process, since it was activated during the process. After that, several backups have been done, and all were full backups.

2) I've done the migration from my previous server several days after.

3) After the migration was finished, I've left the Scheduled backup setup as it was, and during three or four days, I've had only full backups, and high usage of the swap

4) I've disabled the Scheduled backup at least one day. I've reactivated it and changed the time to start the backup from 00:00 am to 08:00 pm. Since then, I have incremental backups and no more high usage of the swap.

 

[Aytalina]

LaurentR2D2,

Thank you for the detailed explanation.

I was able to reproduce the issue with the following scenario: if the first full server scheduled backup was created on an empty server, then all scheduled backups will be full instead of incremental (even when subscriptions are added).

I suggest that it is related to your case since you created a scheduled task right after the deployment and, probably, the first one was without content.

In this case, I confirm the issue, the id is PPP-46628, which is currently under verification from our team. We will include the fix in the nearest Plesk updates.

Thank you for the report.

Best regards,
Aytalina.

 

[LaurentR2D2]

Hello,
There was today two others monitoring alarms concerning high swap usage, both during the backup which was à full backup. It seems that this high swap usage occurs only with full backup, since I had no problems with the,incremental backups this week.