topic Re: Should I read the data from portable external hard drive? in SAS Programming

Should I read the data from portable external hard drive?

Phil_NZ — Thu, 11 Mar 2021 19:39:28 GMT

Hi all SAS Users,

I am wondering if there are too many differences between reading the data from a directory in the portable external hard drive and a directory located in the computer. My portable external hard drive is HDD and the hard disk in my computer also HDD.

The reason I did so because I want the computer having space to run the code.

Warm regards.

Re: Should I read the data from portable external hard drive?

SASKiwi — Thu, 11 Mar 2021 20:04:17 GMT

There is no difference between the two as far as SAS is concerned except the external drive may have slower performance.

Re: Should I read the data from portable external hard drive?

ballardw — Thu, 11 Mar 2021 20:13:12 GMT

You may find, depending on everything you do, that the drive letter changes as well. Like insert a thumb drive before connecting the external drive.

So extra care may be needed if reusing program code.

Re: Should I read the data from portable external hard drive?

Reeza — Thu, 11 Mar 2021 20:16:38 GMT

Did you verify if you were running a server or local installation? That matters a lot for a question like this.

Re: Should I read the data from portable external hard drive?

Phil_NZ — Thu, 11 Mar 2021 20:20:31 GMT

Hi @Reeza

I am running on SAS EG remotely server, not locally installed. Hope that I understand you correctly.

Warm regards.

Re: Should I read the data from portable external hard drive?

Phil_NZ — Thu, 11 Mar 2021 20:22:43 GMT

Hi @ballardw

Thank you for your suggestion.

Can I ask what does "drive letter changes" mean, please? So, you mean be careful about the directory reference (folder pathway), did I explain you properly?

Warm regards.

Re: Should I read the data from portable external hard drive?

ballardw — Thu, 11 Mar 2021 20:46:47 GMT

@Phil_NZ wrote:

Hi @ballardw

Thank you for your suggestion.

Can I ask what does "drive letter changes" mean, please? So, you mean be careful about the directory reference (folder pathway), did I explain you properly?

Warm regards.

At least in my Windows experience the permanent drives and/or drive partitions installed will have the letters C, D (and so on) in the order they were set up. My current set up goes to drive F: for the DVD drive.

If I plug a thumb drive into a USB port it gets the next available drive designation G:. If I plug in my portable external drive it gets H:. If I disconnect both and then reconnect the portable external drive the next time it will get the letter G:. So the paths change. The main concern is if you remove and reconnect items in a different order then any code using those paths needs to be addressed very carefully as they may change. UNC strings may be a work around but I haven't tried them with removable media. This may point to some other approaches:

https://support.sas.com/documentation/cdl/en/hostwin/69955/HTML/default/viewer.htm#n07buc7sg08fdrn1c1jmmr8hl78r.htm

I suspect similar happens on a Linux/Unix but don't have any experience (my last Linux box died before I had a thumb drive).

Re: Should I read the data from portable external hard drive?

Phil_NZ — Thu, 11 Mar 2021 20:50:43 GMT

@ballardw

Ahhhh, I see what you mean, I never plug in my USB inside so it does not change, but good experience for me in the future.

Thank you very much for your experience

Warm regards.

Re: Should I read the data from portable external hard drive?

Kurt_Bremser — Thu, 11 Mar 2021 20:51:57 GMT

Then the file in question needs to be uploaded to the server anyway, which is usually a manual process, unless you want to use the Copy Files task (provided by EG) in a project for automation..

@Phil_NZ wrote:

Hi @Reeza

I am running on SAS EG remotely server, not locally installed. Hope that I understand you correctly.

Warm regards.

Re: Should I read the data from portable external hard drive?

Phil_NZ — Thu, 11 Mar 2021 20:57:49 GMT

Hi @Kurt_Bremser

Sorry in advance if I explain you inappropriately!

So, you mean that in my case, there is no well-taken difference between calling a dataset from an external hard drive and the same dataset from an existing hard drive (says disk C or D).

Warm regards.

Re: Should I read the data from portable external hard drive?

Kurt_Bremser — Thu, 11 Mar 2021 21:21:22 GMT

When SAS runs on a remote server, it has no access to a portable drive connected to your desktop PC.

So you will need to upload first, anyway.

Re: Should I read the data from portable external hard drive?

Reeza — Thu, 11 Mar 2021 21:39:01 GMT

Then it doesn't matter at all. You need to upload your data to the server and that takes time regardless, and once its there the space on your computer is entirely irrelevant. All the work happens on the server and you only see the results. Your computer resources should not be massively effected, except when displaying graphical output.

Re: Should I read the data from portable external hard drive?

Phil_NZ — Thu, 11 Mar 2021 22:45:50 GMT

Hi @Reeza and @Kurt_Bremser

Thank you for your explanation. Can I ask the same question in case SAS is installed locally in the computer, please?

Many thanks and warm regards.

Re: Should I read the data from portable external hard drive?

Kurt_Bremser — Thu, 11 Mar 2021 22:54:35 GMT

You can use the external drive for backup purposes, but for work, the internal drive is usually better. And nothing speeds a PC up better than a internal SSD drive.

Re: Should I read the data from portable external hard drive?

Reeza — Thu, 11 Mar 2021 23:56:41 GMT

There are too many other factors to offer a conclusive answer. A SSD connected via USB 2.0 is less reliable than an installed SSD. A SSD on a network drive that's being scanned or backed up may be significantly slower to write to than an external drive. If you're only reading and not writing files it's different and it's different again if you're planning to redirect your full work directory to the external drive versus your local drive.
And if you're using Viya it's different again, as that supports in memory operations.

Most places that have a Server are usually connecting to a data warehouse or data server and there's well defined processes for the ETL so its usually not something a statistician or analyst would worry about. The cases where you require external data should be rare and should be smaller data files. Otherwise why would you invest millions in a software solution like SAS?

Re: Should I read the data from portable external hard drive?

Phil_NZ — Thu, 11 Mar 2021 23:59:52 GMT

Hi @Kurt_Bremser

Yes, I see, @Kurt_Bremser

I just think of buying a laptop i7 with 556 SSD this morning to smash this project. I also believe that the internal storage would be much better than the external one.

Thank you for your bits of help!

Re: Should I read the data from portable external hard drive?

Reeza — Thu, 11 Mar 2021 23:58:29 GMT

SAS isn't running on your computer, your SSD or processor shouldn't affect your run times besides how long it takes to display the results.

Re: Should I read the data from portable external hard drive?

Reeza — Fri, 12 Mar 2021 00:01:14 GMT

@Kurt_Bremser wrote:

You can use the external drive for backup purposes, but for work, the internal drive is usually better. And nothing speeds a PC up better than a internal SSD drive.

Check with your IT team before doing this. Data is now on your laptop, not in a secure environment and that often is against company rules. Your backups are also entirely manual and not 'backed up' so if your laptop is destroyed you lose it all. I don't back up to a local drive unless it's a learning or personal project, where I don't care if it gets blown away. Your program files are text and small enough to not matter.