We are just beginning at looking at what it will take to convert our traditional FTP transmissions to SFTP transmissions. I know using ssh SFTP on the zOS mainframe environment for transmitting traditional MVS datasets that one must first copy the MVS dataset to a (OMVS) unix file which is then used by the ssh SFTP program to ship over to the remote location. Our concern is that we are often transmitting numerous MVS datasets that are GBs in size, so we are worried about configuring an OMVS (zFS) directory structure that would be large enough to support all of these temporary unix files required by the SFTP process. With that in mind we were wondering if the CoZ SFTP process/software eliminates the need of first having to copy the source MVS dataset to a corresponding OMVS unix file before performing the SFTP transmission? Any insight on how this works with CoZ SFTP would be greatly appreciated.
Thanks,
Brad
ssh SFTP unix file requirement when using CoZ SFTP
Re: ssh SFTP unix file requirement when using CoZ SFTP
Brad,
Co:Z SFTP allows for direct transfer to and from z/OS data sets and never stages data in USS files or in shared memory. We have many users that actively transfer very large datasets with Co:Z.
Note, however, that if you are migrating from FTP, you will see an increase in CPU usage due to the cost of encryption. You will see these costs with any secure method, but you should be aware of this.
I would recommend that you download and use Co:Z under our free Community License to evaluate it. You can download the latest version of the software here: https://www.dovetail.com/downloads/coz/index.html The installation takes about 10 minutes. You should refer to our IBM Ported Tools OpenSSH quick install guides for information about tuning z/OS OpenSSH to get the best experience. Here's the relevant web page: https://www.dovetail.com/docs/coz/coz_index.html
Co:Z SFTP allows for direct transfer to and from z/OS data sets and never stages data in USS files or in shared memory. We have many users that actively transfer very large datasets with Co:Z.
Note, however, that if you are migrating from FTP, you will see an increase in CPU usage due to the cost of encryption. You will see these costs with any secure method, but you should be aware of this.
I would recommend that you download and use Co:Z under our free Community License to evaluate it. You can download the latest version of the software here: https://www.dovetail.com/downloads/coz/index.html The installation takes about 10 minutes. You should refer to our IBM Ported Tools OpenSSH quick install guides for information about tuning z/OS OpenSSH to get the best experience. Here's the relevant web page: https://www.dovetail.com/docs/coz/coz_index.html
Re: ssh SFTP unix file requirement when using CoZ SFTP
Thank you very much for the great response and that is great news. Yes, I already downloaded the manuals and the coz-4.2.0.bin install file, and just as you recommended, we were planning on trialing it and if it met all of our needs then we were planning on pursuing the potential purchase of a license to obtain full support.
One last question, do I need CoZ SFTP s/w implemented on both the client and server side of the transmission to take advantage of the CoZ features? I personally support the mainframe environment, but many of our FTPs transfer large MVS (sequential) datasets to distributed servers (i.e. Unix & Windows) and NAS storage. Subsequently I wasn't sure if I needed to have CoZ running on both sides of the transmissions. This would be difficult to implement on all of our distributed platforms. Even if I wanted to simply perform a SFTP between two zOS lpars to transmit a large MVS dataset without having to first copy the file to an OMVS unix file, then would I have to have CoZ running on both the client & server side of this connection? I'm thinking I probably would need to have CoZ SFTP running on all the mainframe lpars to truly avoid the OMVS unix file conversion step.
One last question, do I need CoZ SFTP s/w implemented on both the client and server side of the transmission to take advantage of the CoZ features? I personally support the mainframe environment, but many of our FTPs transfer large MVS (sequential) datasets to distributed servers (i.e. Unix & Windows) and NAS storage. Subsequently I wasn't sure if I needed to have CoZ running on both sides of the transmissions. This would be difficult to implement on all of our distributed platforms. Even if I wanted to simply perform a SFTP between two zOS lpars to transmit a large MVS dataset without having to first copy the file to an OMVS unix file, then would I have to have CoZ running on both the client & server side of this connection? I'm thinking I probably would need to have CoZ SFTP running on all the mainframe lpars to truly avoid the OMVS unix file conversion step.
Re: ssh SFTP unix file requirement when using CoZ SFTP
The short answer is that you only need Co:Z on the system where you plan to read/write z/OS data sets.
The Co:Z SFTP server is specifically designed to be able to work with any SFTP client that correctly implements the SFTP specification. This means for example that the OpenSSH SFTP clients on most Linux distros work fine with Co:Z, and are able to transfer files directly from and to data sets.
This section of the user's guide describes how to use a standard client to interact with the Co:Z SFTP server: https://dovetail.com/docs/sftp/using.html
On the z/OS side there is a custom Co:Z SFTP client that enables access to z/OS artifacts, including data sets. Most of our users run the client under batch: https://dovetail.com/docs/sftp/client.html#client-batch but it is also runs interactively under a z/OS Unix System Services session, and behaves like a standard SFTP client with some additional z/OS capabilities.
If you want to run z/OS to z/OS transfers using data sets on both sides, you will need to have Co:Z installed on both z/OS images.
The Co:Z SFTP server is specifically designed to be able to work with any SFTP client that correctly implements the SFTP specification. This means for example that the OpenSSH SFTP clients on most Linux distros work fine with Co:Z, and are able to transfer files directly from and to data sets.
This section of the user's guide describes how to use a standard client to interact with the Co:Z SFTP server: https://dovetail.com/docs/sftp/using.html
On the z/OS side there is a custom Co:Z SFTP client that enables access to z/OS artifacts, including data sets. Most of our users run the client under batch: https://dovetail.com/docs/sftp/client.html#client-batch but it is also runs interactively under a z/OS Unix System Services session, and behaves like a standard SFTP client with some additional z/OS capabilities.
If you want to run z/OS to z/OS transfers using data sets on both sides, you will need to have Co:Z installed on both z/OS images.