Solution:

Go to Synology and open the VPN server. Open the settings menu for L2TP/IPSec VPN.

Remove the checkmark from “Enable SHA2-256 compatible mode (96 bit)”.

Der Beitrag Solved: iPhone and Mac do not connect to Synology L2TP/IPSec VPN: The L2TP-VPN server did not respond erschien zuerst auf Pixelfriedhof.

Why Western Digital at all?

I have been using WD hard drives in network storage since 2006. Whether in my first Netgear NAS, later the QNAP or in the subsequent Synology NAS. In this time I have not once experienced a failure of a WD hard drive. Once there were S.M.A.R.T. errors with a disk after 4 years of runtime – but that’s okay after this runtime. I personally have not had such good experiences with Toshiba and Seagate disks, frequent errors, too early failures. The plates of the competition are a bit cheaper, but for the few bucks more, you can buy more security with Western Digital. And whether I spend 800€ or 750€ for a complete NAS, that doesn’t really make the difference in terms of reliability.

CMR vs. SMR hard disks – in RAID it is better to use CMR only

The following explanation is very pictorial and not technically completely correct, but it explains the facts even for non-experts.

In CMR (Conventional Magnetic Recording), data is written to a hard disk with a generous gap between the previous and subsequent data blocks. The read and write head can imprecisely and quickly jump to the gap, search for the end of the gap and read or write the data then starting. Each gap, of course, eats up a bit of memory.

With SMR (Shingled Magnetic Recording) the gaps are reduced. The aim is to have more storage space. However, the read and write head must be positioned more precisely at the data block to be processed and this may take a little longer than with an imprecise approach. The whole concept works – but not in a RAID system. With many read and write operations it can happen that the data sent by the RAID controller to the hard disks cannot be written in time. This results in a backlog. If the buffer is full, RAID synchronization errors follow.

These errors caught the attention of the German specialist website Heise.de in April 2020. Link
As of June 2020, the major HDD manufacturers themselves warned against SMR HDDs in NAS and RAIDs. Link

Long Story Short: Only use hard disks with CMR technology in the NAS.

List of all compatible CMR NAS hard drives from Western Digital

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If you try uploading a large source of files to a cloud backupstorage via “Hyper Backup” you might encounter a problem where your backup gets stuck immediately after a connection loss. Especially when creating the initial backup-set, which uploads all files that are available at the source, the job might need a few days to complete. It is very likely, that during this long time there will be a connection-loss or a connection-reset by your ISP which will freeze the procedure. So you might think: “I’ll never get my data into the cloud”.

Don’t give up, there is a workaround. 

To understand the workaround you first have to understand how “Hyper Backup” works. After the initial backup-set (the first time you upload the source-files to the backup-destination), in future backup-tasks “Hyper Backup” only updates or adds altered or new data, which means, that the following backups are far smaller as they only contain everything that is not already at the destination. Depending on how your backup-task is configured and scheduled, we might speek of incremental and differential backups.

This behaviour is the key to our workaround. Most people suffering from this problem, will not have this problem with the everyday-backup-tasks, but with the first initial backup, as it is much larger as I explained above. So we need to only workaround the initial backup-task.

In my case, my destination for the backups is the cloudstorage-provider “hubiC” but this should be similar when using other providers.

My backup-source is for example 250GB large, which is not uploadable within one day because of compression-time and encryption-time. My ISP resets the Internetconnection at 1pm and the backup gets stuck.

Let’s say that my backup-source, my share to backup, consists of 25 folders. If I try to upload every 25 folders at once it will fail, so we go to configure our backup-task to initially only backup folders 1 to 3.

We start the backup-task and folders 1 to 3 are successfully uploaded in less than a day.

Now we reconfigure the backup-task, adding folders 4 to 6 and start the backup again (meaning we have now activated folders 1, 2, 3, 4, 5, and 6 to be uploaded).

As I mentioned above, only new or altered files, in this case folders 4 to 6 will be uploaded. This procedure will also finish within one day.

Repeating this until folder 25, this workaround allows us to partially upload our whole source. When every folder was uploaded, we go to our backup-settings once again and activate the whole share at the higher root level.

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