Category Archives: Storage

Migrating from Synology DS415+ to DS916+

Today I migrated from a Synology DS415+ (upgraded to 8 GB myself) to a brand-new, unused Synology DS916+ (8 GB factory equipped.)

I followed the instructions given by Synology, but as my actual experience was considerably different (actually easier!) from what supposedly should have happened, I’m documenting them here for reference.

I started by upgrading the old unit to the latest DSM version, and then shutting it down. I moved all four hard drives to the new unit, making sure the same order of the drives in the drive bays was maintained.

I then switched on the new unit and launched the web UI in a browser. This is what I got:

synology-migration-01 Continue reading Migrating from Synology DS415+ to DS916+

Synology refuses to admit annoying “Cloud Sync” Bug

Since about half a year I’m struggling with a very annoying bug in Synology’s “Cloud Sync” package I’m running on my expensive Synology DiskStation DS415+ NAS. It is still present as of today’s DSM 6.0.2-8451 Update 2.

I would like to backup my photos to my Amazon Drive/CloudDrive. As an Amazon Prime customer I can store an unlimited number of images, and only images — other files, like *.xmp sidecar files, will count against my general 5 GB limit.

The problem is that Synology’s Cloud Sync will upload the sidecar files, even though I explicitly only select “Images” to be backed up (and *.xmp is not part of Images, as I will show you!). Continue reading Synology refuses to admit annoying “Cloud Sync” Bug

Remove sensitive files from Synology debug.dat

Sometimes Synology support ask that you support a debug log. This can be done by launching the Support Center application. Then go to Support Services > Log Generation > push button “Generate logs”.

If you are concerned that you might give them sensitive information you can clean up the debug.dat file and remove the sensitive files from it.

I wrote a quick shell script that should runs under Mac OS X, but should also run under Linux. Here it is:


if [ -z "${DEBUG_FILE}" -o -z "${NEW_FILE}" ]; then
    echo "You must specify the path to the debug AND to the new file, quitting..."
    exit 1

if [ -z "$TMPDIR" ]; then

PROG="`basename $0`"

if [ ! -r "${DEBUG_FILE}" ]; then
    echo "Debug file ${DEBUG_FILE} is unreadable, quitting..."
    exit 1

if [ -f "${NEW_FILE}" ]; then
    echo "New file ${NEW_FILE} already exists, quitting..."
    exit 1

EXCLUDE_PAT="`mktemp -t ${PROG}`" || exit 1

cat >"${EXCLUDE_PAT}" <<EOF

tar cfz "${NEW_FILE}" -X "${EXCLUDE_PAT}" @"${DEBUG_FILE}"

rm -f ${EXCLUDE_PAT}

If this is helpful for anybody, please let me know by commenting on this article.

Terratec Cinergy Hybrid XE not working on Synology

Even on the latest 5.1-5021 version of Synology‘s DSM I couldn’t get my Terratec Cinergy Hybrid XE working on my Synology NAS — the corresponding kernel module tm6000 would always generate a general protection fault on my DS414.

Today I upgraded to a DS415+ (with a completely different CPU), and the module still crashes.

So it seems it’s a real bug in the driver, not just a defect on a single platform (which can happen e. g. due to compiler bugs).

Update 2015-06-19:

Unfortunately Synology seem not very interested in this kind of problems. I repeatedly reported this issue, but all they replied is “Thanks for your report, we’re looking into this.” Even in the latest DSM release 5.2 the issue is still present.

MSI Mega Sky 580 DVB-T Stick Support dropped by Synology

MSI Mega Sky 580 DVB-T stick users beware:

With DSM 5.0-4493 Update 4 for my DS414 Synology suddenly deliberately disabled support for my MSI Mega Sky 580 DVB-T stick.

I did not immediately notice this, since Synology do not warn you that you device has been disabled. So I missed a couple of programmes I wanted to record for my kid — thank you so much, Synology! :-(

I downgraded to DSM 5.0-4493 and then installed Update 3 again, and my stick is still working.

Let’s see how Synology react to my complaint. If they will not enable my stick again I will complain to Amazon where I bought the device from — let’s see how they will respond…

Synology’s speed lie

Since a while I own a new Synology NAS, a DiskStation DS414. Synology advertizes this model with speeds of

Over 207.07MB/s Reading, 135.63MB/s Writing

However I never came even close to those speeds in my daily use of the DiskStation, so I tried to set up an ideal scenario in which I would get the fastest speed the NAS could deliver.

I did so by using a very fast client (a MacBook Pro Retina with a 2.5 GHz Core i7 CPU and SSD drive), and connected that directly “back-to-back” (i. e. without any network device in-between that could potentially slow the network traffic down) to one of the networking ports of the NAS.

The NAS contains three hard drives, a Western Digital WD30EURS (3 TB, max. speed according to benchmarking >130 MByte/s both reading and writing), a Seagate ST32000542AS (2 TB, max. speed at least 109 MByte/s), and a Western Digital WD40EFRX (4 TB, max. speed 146 MByte/s), in a SHR compound (technically a form of RAID5, so due to the striping involved speed should increase compared to a single drive configuration).

I then copied about 25 GB of large files (movies) between the Mac and the NAS.

The fastest speeds I could get was a meager 79.5 MByte/s on reads, and 39.4 MByte/s on writes. That was extremely disappointing, but it confirmed my subjective feeling that the NAS is slow.

To confirm the read data rates I executed the following command directly on the NAS, to have a means of a “plausibility check:”

nas1> hdparm -t /dev/sda /dev/sdb /dev/sdc

 Timing buffered disk reads: 328 MB in  3.01 seconds = 109.09 MB/sec

 Timing buffered disk reads: 332 MB in  3.00 seconds = 110.66 MB/sec

 Timing buffered disk reads: 392 MB in  3.00 seconds = 130.66 MB/sec

This shows that the NAS is capable of reading at a higher speed than it could deliver to the client via the network — possibly an issue with the CPU being too weak to deliver the full speed Synology promise?

Anyway, I find these disappointing results inacceptable, and it makes Synology’s statement a “lie.” Also, I found severe instability and defects with respect to the VideoStation package and recording from a DVB-T stick. Plus the massive issues Synology have with the power-saving “Hibernation” feature that never worked for me (neither on this box, nor on its predecessor DS212+.) And I’m not alone, a lot of people have the same issue, but Synology seem unable to solve it.

Considering the high price of the NAS (almost 400 EUR!), my strong opinion is that the device simply is not worth its money. It would have been better to buy a HP ProLiant MicroServer and get more power for less money. :-(

Encrypted TimeMachine backups on network share

Mac OS normally doesn’t allow you to use network shares as targets for TimeMachine backups. This can be worked around, tho. :-)

First you need to tweak Mac OS to accept network shares by entering the following command in a Terminal session:

defaults write TMShowUnsupportedNetworkVolumes 1

That would already allow you to store your backups on a network share. But do you really want to trust your valuable data to a network share that can potentially be accessed by untrusted users, such as your favorite bastard admin from hell?! :)

Here’s when the following comes in:

You will create an encrypted sparse bundle and use it as a target for the backup.

Continue reading Encrypted TimeMachine backups on network share