How can I find out what is happening? (case #18901615)

What about

# du -csh /var/log/*

and

# du -csh /var/log/frontview/*

Here you go:

ianch-nas:~# du -csh /var/log/*
912k    /var/log/auth.log
1.1M    /var/log/cron.log
1.3M    /var/log/cups
130M    /var/log/daemon.log
16k     /var/log/ddns
240k    /var/log/debug
16k     /var/log/dmesg
576k    /var/log/exim
139M    /var/log/frontview
16k     /var/log/fsck.log
4.8M    /var/log/kern.log
16k     /var/log/ksymoops
16k     /var/log/LeafP2P.log
128k    /var/log/LeafP2P.log.old
0       /var/log/lpr.log
0       /var/log/mail.log
4.1M    /var/log/messages
256k    /var/log/mt-daapd.log
144k    /var/log/netatalk.log
944k    /var/log/netatalk.log.old
16k     /var/log/ntpstats
128k    /var/log/proftpd.log
16k     /var/log/raidiator_version
16k     /var/log/ReadyNAS_Remote.log
144k    /var/log/rsyncd.log
624k    /var/log/samba
0       /var/log/slimserver.log
135M    /var/log/syslog
2.0M    /var/log/upnp-av.log
128k    /var/log/user.log
421M    total
ianch-nas:~# du -csh /var/log/frontview/*
2.2M    /var/log/frontview/access.log
134M    /var/log/frontview/backup
1.2M    /var/log/frontview/command.log
16k     /var/log/frontview/config_backup_restore.log
16k     /var/log/frontview/disk_smart_2012_06_17.log
16k     /var/log/frontview/disk_smart_2012_06_24.log
16k     /var/log/frontview/disk_smart_2012_07_01.log
16k     /var/log/frontview/disk_smart_2012_07_08.log
16k     /var/log/frontview/disk_smart_2012_07_15.log
16k     /var/log/frontview/disk_smart_2012_07_22.log
16k     /var/log/frontview/disk_smart_2012_07_29.log
16k     /var/log/frontview/disk_smart_2012_08_06.log
16k     /var/log/frontview/disk_smart_2012_08_13.log
16k     /var/log/frontview/disk_smart_2012_09_05.log
16k     /var/log/frontview/disk_usage.log
16k     /var/log/frontview/ecounter_2012_08_13_0000.log
16k     /var/log/frontview/ecounter_2012_08_14_0000.log
16k     /var/log/frontview/ecounter_2012_08_15_0000.log
16k     /var/log/frontview/ecounter_2012_08_16_0000.log
16k     /var/log/frontview/ecounter_2012_09_05_1434.log
16k     /var/log/frontview/enclosure.log
320k    /var/log/frontview/error.log
16k     /var/log/frontview/memory.log
16k     /var/log/frontview/msmtp.log
16k     /var/log/frontview/partitions_2012_06_17.log
16k     /var/log/frontview/partitions_2012_06_24.log
16k     /var/log/frontview/partitions_2012_07_01.log
16k     /var/log/frontview/partitions_2012_07_08.log
16k     /var/log/frontview/partitions_2012_07_15.log
16k     /var/log/frontview/partitions_2012_07_22.log
16k     /var/log/frontview/partitions_2012_07_29.log
16k     /var/log/frontview/partitions_2012_08_06.log
16k     /var/log/frontview/partitions_2012_08_13.log
16k     /var/log/frontview/partitions_2012_09_05.log
16k     /var/log/frontview/raid_config_2012_06_17.log
16k     /var/log/frontview/raid_config_2012_06_24.log
16k     /var/log/frontview/raid_config_2012_07_01.log
16k     /var/log/frontview/raid_config_2012_07_08.log
16k     /var/log/frontview/raid_config_2012_07_15.log
16k     /var/log/frontview/raid_config_2012_07_22.log
16k     /var/log/frontview/raid_config_2012_07_29.log
16k     /var/log/frontview/raid_config_2012_08_06.log
16k     /var/log/frontview/raid_config_2012_08_13.log
16k     /var/log/frontview/raid_config_2012_09_05.log
16k     /var/log/frontview/smart_errors_hdc
16k     /var/log/frontview/smart_errors_hde
16k     /var/log/frontview/smart_errors_sda
16k     /var/log/frontview/smart_errors_sdb
80k     /var/log/frontview/spool.err
240k    /var/log/frontview/spool.log
16k     /var/log/frontview/status.log-new
176k    /var/log/frontview/status.log-old
16k     /var/log/frontview/ups.log
139M    total

Looks like daemon.log and syslog haven't been truncated properly. The backup job logs probably haven't either. It'd be trying to give you a download of about 300-400 MB at the moment when you attempt to download your logs. Would be best to let support login remotely and fix the issue. Since you have SSH access they could do it via SSH. You could port forward port 22 and let them know the SSH password (you can change it first if you like using the "passwd" command).

After waiting over 2 weeks for Support to respond to a system down problem (with no fix) , I haven't the energy to log a new case to clean out the log files. I followed Dave's advice (again) and cleaned them out myself and I can download the logs zip file with no issues. Everything is working fine again ..

Really feel let down by Netgear here. What with poor AFP performance, recent bad quality firmware upgrades, lengthy beta programmes to get important fixes, system crashes when doing simple tasks, no support when I needed it, etc. I am afraid that this is the last ReadyNAS I am buying