RN104 randomly freezing since update to 6.2.0 (curr. 6.2.2)

Hello,

since i upgraded my RN104 to OS 6.2.X the NAS randomly freezes every couple of days (no front-end, no SSH and no reply to pings). The only way to get access again to the RN104 is disconnecting / connect the powercable.
First I suspected that the freezes are related to my backup jobs as I had an issue with NTFS (see http://www.readynas.com/forum/viewtopic.php?f=7&t=78879) but I did change the backup HDDs to EXT4, ran the backup jobs manually without any problems and disabled them afterwards to exclude this cause. Still the RN104 freezes randomly.

One big issue is that I cannot find any clue in the log files. I checked them several times after the crashes and the last entries correspond to some cron jobs being executed. The following job caught my attention because usually the system crashes happen sometimes after this one has been executed:

Dec 31 08:09:01 nas /USR/SBIN/CRON[9005]: (root) CMD (  [ -x /usr/lib/php5/maxlifetime ] && [ -d /var/lib/php5 ] && find /var/lib/php5/ -depth -mindepth 1 -maxdepth 1 -type f -ignore_readdir_race -cmin +$(/usr/lib/php5/maxlifetime) ! -e
xecdir fuser -s {} 2>/dev/null \; -delete)

According to my research there have been some issues regarding this job and ubuntu / debian systems:

https://bugs.debian.org/cgi-bin/bugrepo ... bug=633100
https://bugs.launchpad.net/ubuntu/+sour ... ug/1356113
https://bugs.launchpad.net/ubuntu/+sour ... bug/877894
https://www.flynsarmy.com/2011/11/fuser ... ntu-11-10/

Due to that and after checking out the forum, where I came across this post viewtopic.php?f=65&t=79141 which mentions a possible memory leak, I decided to setup a cron job to monitor the memory usage.
The log indicates that something strange happens as the swap usage is slowly increasing and but I cannot find any processes which are acutally using swap space (bash: for file in /proc/*/status ; do awk '/VmSwap|Name/{printf $2 " " $3}END{ print ""}' $file; done | grep kB). Though the swap usage is not very high when the system crash happens (last crash after TIME:08:10:01 mark):

TIME:08:08:01
             total       used       free     shared    buffers     cached
Mem:        507188     482900      24288          0      40232     165996
-/+ buffers/cache:     276672     230516
Swap:       523964        144     523820

TIME:08:09:01
             total       used       free     shared    buffers     cached
Mem:        507188     483980      23208          0      40304     166104
-/+ buffers/cache:     277572     229616
Swap:       523964        144     523820

TIME:08:10:01
             total       used       free     shared    buffers     cached
Mem:        507188     483396      23792          0      40376     166212
-/+ buffers/cache:     276808     230380
Swap:       523964        144     523820

TIME:08:27:01
             total       used       free     shared    buffers     cached
Mem:        507188     262836     244352          0       6656     143568
-/+ buffers/cache:     112612     394576
Swap:       523964          0     523964

TIME:08:28:03
             total       used       free     shared    buffers     cached
Mem:        507188     485304      21884          0       4692     205772
-/+ buffers/cache:     274840     232348
Swap:       523964          0     523964

TIME:08:29:01
             total       used       free     shared    buffers     cached
Mem:        507188     482048      25140          0       9584     195600
-/+ buffers/cache:     276864     230324
Swap:       523964          0     523964

TIME:08:30:01
             total       used       free     shared    buffers     cached
Mem:        507188     459456      47732          0       3784     184444
-/+ buffers/cache:     271228     235960
Swap:       523964          4     523960

In addition I monitor the running processes of the system but I could not find anything yet. If required I can attach log files.

Today I came across this post viewtopic.php?f=65&t=79284, which states that others have similar issues. I did not reinstall the OS nor did I reset the system to factory defaults as I do not want to ''loose'' my data, but according to the post it did not have the desired effect. I never experienced those issues while using readynas OS 6.1.X.

System details:
Services: SMB, HTTP, HTTPS, SSH, ReadyDLNA, Anti-Virus
Disks: 2x4 TB Segate disks (ST400VN000-1H4168) with RAID 1 and checksums are enabled
Shares: 7 shares, 4 with bit-rot protection and 3 without. No snapshots
Third party Apps: Anti-Virus Plus, SMB Plus, Syslog Server, linux-dash, LogAnalyzer (currently disabled)
Network: Bound Adaptive Load Balancing, WOL enabled
Additional: 4 users and UPS protected, all backup jobs disabled, no external drives, no disk spindown, no power scripts, no clean/defrag/sync jobs

My plan for now is that I will monitor the system behaviour for some more weeks. First I'll run a mem-test from the Boot-Menu (maybe also a Disk-Test) to check for bad RAM. I'll also disable all services except SMB, HTTPS and SSH and see if this has any effect. I could also disable bit-rot protection for all drives and checksums to check if it helps. If any of the mentioned measure fix the issue and I have a stable system for at least 2 weeks I will step by step enable the deactivated functionality and to see what could cause the issue.
Last but not least I could uninstall all third party apps to clean up the system or do a factory reset and reinstall the OS from Boot-Menu to see if things get better, but as mentioned before I do not really want to do this and it seems as it has no effect. I also could grant remote access to my RN104 if that helps to figure out the problem.

I am willing to help to resolve this issue within certain limits, but I also think that netgear should put some effort into reproducing and resolving the issue asap.

Otherwise I would like to go back to OS 6.1.9 until the issues are resolved as me and my family actually are relying on the data on the NAS. How can I downgrade the system?