NAS326 data corruption

MarkusDesk

The NAS326 is silently corrupting data transferred to it. Mostly large files or backups. Sometimes it freezes during transfer, sometimes it just silently corrupts the data.

I saw there are other post about this problem, but it doesn't seem to have a solution. Is there a firmware to fix this problem?

As there is no purpose of keep using the NAS326 as the data saved to it is not reliable at all!

Hill

Do you transfer many files at once, or transfer a single big file? 

Does the NAS 326 also freeze when transferring the data from NAS?

 

MarkusDesk

Hi, it happens while it is writing to the NAS. I received an answer from Zyxel support and they were able to reproduce the problem and acknowledged it.

Unfortunately, they told me they will not fix it as the product is at end of life. So this is to warn everyone who uses the NAS326 to store backups or value files: Your files will be silently corrupted! So do not rely on NAS326 for primary backup or storage purposes. 

Mijzelf

Did ZyXEL tell what causes the problem?

MarkusDesk

Hi,

Unfortunately, no... Zyxel didn't disclose the cause of the problem. They just told me the NAS326 is at end of life and they will not fix it.

znas4home

MarkusDesk said:

The NAS326 is silently corrupting data transferred to it.

Do you mean it corrupts data transferred by SMB/CIFS? What about FTP/SFTP?

MarkusDesk

Hi, yes the NAS326 silently corrupts data transferred by SMB/CIFS. You will only find it is corrupt when you need the data. I don't use the NAS for FTP/SFTP transfer, so I didn't test FTP transfers.

Zyxel_Jerry

Dear @MarkusDesk

Apologize for your inconvenience.

Since NAS326 was launched in 2015, single file with 4TB file size transferring is not a considered application when it was launching. Hence, we’re not able to transfer a single big data 4TB to the NAS 326,

In this case requirement, the NAS542 will be the recommended model which can support single jumbo file (4TB data transferring)

Thank you for the valuable feedback, your application will be considered when we launch the next generation model.

Best regards,

Jerry

Mijzelf

@Zyxel_Jerry , do you know what exactly is the problem? Big files, but how big, and why?

which can support single jumbo file (4TB data transferring)

What has jumbo frames to do with it?

MarkusDesk

Hi,

Just to make it more clear:

1- You still can buy the NAS326 nowadays and as a NAS, it should not silently corrupt files. This is a HUGE problem! And to make things worst, the support just told they can do nothing about that! It is a firmware design flaw!

2- The data corruption happens with files smaller than 4TB too, I got corrupted data even with files smaller than 1TB. The 4TB file transfer just makes it easier to spot the problem.

3- Another way to check that is when using backup imaging software, like Acronis or Macrium. If you check the files generated, these software will detect the backup files are corrupted.

So I have a NAS326 brick, as it is not reliable as NAS and Zyxel didn't even care to solve the problem...

Mijzelf

@MarkusDesk You can easily reproduce it? I have a theory about what is wrong. Well, sort of. On the Doozan forum I read that when running Debian on this box, the performance of Samba is significantly worse, while in theory it runs the same samba server. (Another revision, but basically the same source). So I think the manufacturer of this box, Mitrastar, has applied some optimizations, which improved throughput on cost of stability. They have done that before, samba on the STG212 was also over-optimized. See this.

Some time ago I wrote an Entware-ng package to inject another Samba server in the firmware of the NSA NASses, because W10 dropped SMB1 support, while those boxes didn't support SMB2 or higher. I didn't make that package available for the NAS series, as they were running a samba version which was newer than the one in Entware-ng. But it should be easy to install it on a NAS326, in which case the whole samba server is exchanged by a vanilla one.

When I'm right the throughput will drop, while the stability rises. If you can easily reproduce the problem, it would be nice to know if the samba server is the problem.

1- You still can buy the NAS326 nowadays

Are you sure about being able to buy it? I did a search and at all big resellers the box is out of stock, and Amazon mentions 'We don't know when or if this item will be back in stock.'.

I think if you can find one, it's old stock.

Yet I agree that ZyXEL might have longer support. The box was introduced in the end of 2015, and 5 years from brand new to EOS is too short. The hardware lasts much longer. I have a NSA220 here, from 2007, which still works fine. But it's EOS since 2012.

It is a firmware design flaw!

Not necessarily. The optimization of the STG212 was no problem until at client side new optimizations were applied, which triggered the problem. I don't know enough of Samba to be able to judge if the STG212 optimization violated some specification from the beginning.

The same could be true for the NAS326. Maybe it worked fine back in 2016, but changed Microsoft their implementation meanwhile. (And they did. For instance SMB1 was dropped). Yet it would be to ZyXEL's credit if they would solve the problem. I think Synology would have done it. On the other hand, if most people are not hit by this bug, and the solution would have significant impact on the throughput, wouldn't people yell at ZyXEL because they crippled their box?