Slowness on writing files

[gomezdegomera]

Using jcifs-ng library, when writing a file from local folder to an smb folder, I register a transfer rate of about 7MB/s.
Instead, using the windows shell copy function for the same local file and the same smb folder the transfer rate is 80/s (10 times more).
I have the same problem for all files, smb folders and smb shares.
I noticed that transfer rate limit exists on single file; I mean that writing 2 files in parallel the transfer rate is about 14MB/s.

I have this configuration:

jcifsProperties.setProperty("jcifs.smb.client.enableSMB2", "true");
jcifsProperties.setProperty("jcifs.smb.client.useSMB2Negotiation", "true");
jcifsProperties.setProperty("jcifs.smb.client.attrExpirationPeriod", "0");
jcifsProperties.setProperty("jcifs.smb.client.responseTimeout", "70000");
jcifsProperties.setProperty("jcifs.smb.client.soTimeout", "70000");

I'm using code like this:

out = new BufferedOutputStream(fileObject.getContent().getOutputStream());
IOUtils.copy(in, out);

**
Could I have missed some optimization options on smb client?
Could it be a library issue (known one or not)?
Am I using a wrong approach for writing?**

Thanks

[mbechler]

SMB performance largely depends on the read/write buffer/request size. The smaller, the more protocol overhead and also network latency starts to dominate over bandwidth (as every write requires a round-trip). Buffer sizes larger than 64k require the SMB 2.1 multi-credit feature, which unfortunately jcifs-ng does not currently support - therefore it definitely won't be able to achieve the same throughput as windows/samba/.... But you may want to check how large the buffers that IOUtils.copy are and make that at least 64k.