Openmediavault-usbbackup causing crashes

I am running OMV 4.1.35, J3455, 6GB DDR3, 8TB data disk, 60GB appdata disk, 8GB USB root drive, but I have been having this problem for ages. I have 2 USB drives that I use to back up my data; 1 disk which contains video files always works fine, the other disk always causing the server to crash. When the system is rebooted, the backup process appears to complete successfully. I thought that I had solved the issue last week, when my root drive had run out of space due to a large rsync log file. I resized the root drive from 4GB to the full 8GB. However, the problem is still occurring.

I have a monitor connected to the server, and after the server had crashed initially, I held down the power button and the hard disk started doing something, so rather than powering down, I took my finger off the button and the following lines came up on the monitor

FAT-fs (sdd1): FAT read failed (blocknr32)

Out of memory: Kill process 1796 (jellyfin) score 70 or sacrifice child

Killed process 1796 (jellyfin) total-vm:4560928kb, anon-rss:402764kB, file-rss:0kb, shmem ???? (I didn't write this bit down)

sdd1 is the USB drive that usbbackup is backing up to.

I'm not sure what the "Out of memory" refers to?

Having had a think about this and a search on the internet, is it possible that the unassigned 4GB on the USB root drive was originally a swap file that was removed when I installed the flash memory plugin? Would the plugin have removed the swap partition?

So it seems that the error message above is due to the system running out of RAM, so I have 6GB RAM and no swap file, I've seem zram/zswap mentioned a few times, but not really sure how/where to install it

Would bumping the ram up to 8GB help?

below is folder2ram disk space available in the system

folder2ram 2879440 2879440 0 100% /var/log

folder2ram 2879440 0 2879440 0% /var/tmp

folder2ram 2879440 0 2879440 0% /var/lib/openmediavault/rrd

folder2ram 2879440 16 2879424 1% /var/spool

folder2ram 2879440 7668 2871772 1% /var/lib/rrdcached

folder2ram 2879440 4 2879436 1% /var/lib/monit

folder2ram 2879440 0 2879440 0% /var/lib/netatalk/CNID

folder2ram 2879440 820 2878620 1% /var/cache/samba

overlay 57422220 23034492 34371344 41% /sharedfolders/appdata/overlay2/5f470 e25cb4f2812a727f8a9839e499d8c28e173b365cf33d6e4f34c739c9bda/merged

overlay 57422220 23034492 34371344 41% /sharedfolders/appdata/overlay2/f69e1 5d82b088f7eb8edc65f817997868647e847d321ca3c2e69807ba532dfcd/merged

overlay 57422220 23034492 34371344 41% /sharedfolders/appdata/overlay2/9acc4 8404b3bb2bc521684515d9a836701dd06e71e42a1297b59596ceee1eae0/merged

overlay 57422220 23034492 34371344 41% /sharedfolders/appdata/overlay2/d9bd2 c7ae1d462c3f04657edc6e2466674163080b674da2fdd5398b87e58cc00/merged

overlay 57422220 23034492 34371344 41% /sharedfolders/appdata/overlay2/08d9d a4b43d0423b0699b9d275012f698cce51e071447e6f47502f8d4605d53b/merged

overlay 57422220 23034492 34371344 41% /sharedfolders/appdata/overlay2/b825b a8f73ec520983e183919dd7cea7038156c761ef37964529667094a18c7c/merged

and here is the contents of /var/log daemon logs and rsync logs are taking up most of the space

drwxr-xr-x 2 root root 140 Apr 1 00:07 apt

-rw-r----- 1 root adm 4096 Apr 1 13:39 auth.log

-rw-r----- 1 root adm 45056 Mar 29 08:05 auth.log.1

-rw-rw---- 1 root utmp 0 Apr 1 00:07 btmp

-rw------- 1 root utmp 0 Mar 26 14:23 btmp.1

drwxr-xr-x 2 root root 100 Mar 29 08:05 cron-apt

-rw-r----- 1 root adm 201379840 Apr 1 13:39 daemon.log

-rw-r----- 1 root adm 965148672 Mar 29 08:05 daemon.log.1

-rw-r----- 1 root adm 35036 Mar 31 12:00 debug

-rw-r----- 1 root adm 157696 Mar 29 07:58 debug.1

-rw-r--r-- 1 root root 0 Apr 1 00:07 dpkg.log

-rw-r--r-- 1 root root 10898 Mar 29 08:47 dpkg.log.1

-rw-r----- 1 root adm 159744 Apr 1 01:02 kern.log

-rw-r----- 1 root adm 733184 Mar 29 08:02 kern.log.1

-rw-r--r-- 1 root root 292 Apr 1 11:45 lastlog

-rw-r----- 1 root adm 3520 Apr 1 13:17 mail.err

-rw-r----- 1 root adm 7415 Mar 29 07:17 mail.err.1

-rw-r----- 1 root adm 3520 Apr 1 13:17 mail.info

-rw-r----- 1 root adm 7415 Mar 29 07:17 mail.info.1

-rw-r----- 1 root adm 3520 Apr 1 13:17 mail.log

-rw-r----- 1 root adm 7415 Mar 29 07:17 mail.log.1

-rw-r----- 1 root adm 3520 Apr 1 13:17 mail.warn

-rw-r----- 1 root adm 7415 Mar 29 07:17 mail.warn.1

-rw-r----- 1 root adm 122880 Apr 1 13:39 messages

-rw-r----- 1 root adm 569344 Mar 29 08:05 messages.1

drwxr-xr-x 2 root adm 560 Mar 31 12:05 nginx

drwxr-xr-x 2 ntp ntp 40 Feb 15 2018 ntpstats

drwxr-xr-x 2 root root 60 Mar 29 08:44 openmediavault

-rw------- 1 root root 468 Mar 31 12:00 php7.0-fpm.log

-rw------- 1 root root 2442 Mar 28 15:44 php7.0-fpm.log.1

drwxr-xr-x 2 root root 80 Aug 11 2019 proftpd

-rw-r----- 1 root adm 181014528 Mar 31 13:31 rsync.log

-rw-r--r-- 1 root root 834666496 Mar 28 17:35 rsync.log.1

drwxr-x--- 3 root adm 420 Mar 31 15:49 samba

-rw-r----- 1 root adm 0 Mar 31 12:05 syslog

-rw-r----- 1 root adm 215478272 Apr 1 13:39 syslog.1

-rw-r----- 1 root adm 52798 Mar 28 07:33 syslog.2.gz

-rw-r----- 1 root adm 124879 Mar 27 14:44 syslog.3.gz

-rw------- 1 root root 63936 Apr 1 11:28 tallylog

-rw-r----- 1 root adm 8192 Apr 1 04:45 user.log

drwxr-xr-x 2 root root 40 Jan 20 2017 watchdog

-rw-rw-r-- 1 root utmp 0 Apr 1 11:45 wtmp

-rw-rw-r-- 1 root utmp 35328 Mar 31 14:09 wtmp.1

Thanks for your advice ryecoaaron, I got over the issue by tar -ing some of the folders full of small files (like the plex library backup), by reducing the number of files I think I mamanged to avoid the system running out of memory. The rsync log is just the default openmediavault-usbbackup setting, so I don't think that there is any way to reduce the verbosity (if that's a word?).

I'm planning to sort the syslog/issue with system by installing a clean version of OMV 5

Thanks