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Enter the size of the swap partition in MB?

Posted: 21 Jul 2015 14:50
by chris.shelton
I understand what swap size is, but I don't understand why this gets asked upon installation.

Does this partition my boot usb stick? I chose a value of 1024, but isn't this going to create a load of extra writes to my USB stick for virtual memory?

Thanks

Re: Enter the size of the swap partition in MB?

Posted: 22 Jul 2015 21:53
by armandh
you are likely trying to do a full install on flash which is not recommended
if you are doing the embedded there should be an install without swap

Re: Enter the size of the swap partition in MB?

Posted: 23 Jul 2015 10:09
by chris.shelton
armandh wrote:you are likely trying to do a full install on flash which is not recommended
if you are doing the embedded there should be an install without swap
It's an embedded install, not with DATA + SWAP or anything.

In the install & upgrade options menu, I chose number 1 - Install 'Embedded' OS/MBR on HDD/SSD/CF/USB (preferred).

Number 4 says 'Install 'Embedded' OS/MBR without SWAP (for expert). The 'for expert' bit deterred me. Should I be going for this option?

Re: Enter the size of the swap partition in MB?

Posted: 23 Jul 2015 15:52
by armandh
Ive always used the #1 option
but I'm using older N4F

Re: Enter the size of the swap partition in MB?

Posted: 23 Jul 2015 17:02
by crowi
the swap is enabled by default since 9.3.x.x
depending on the amount of memory your system has, you can try to en- or disable it.
I tend to stick to the recommendations, but I don't know either if it will wear out the USB stick or not.
My system is currently in the testing phase on 10.1.x.x (8 GB USB stick, 4GB swap on it by default).

Re: Enter the size of the swap partition in MB?

Posted: 24 Jul 2015 19:17
by JoseMR
chris.shelton wrote:I understand what swap size is, but I don't understand why this gets asked upon installation.

Does this partition my boot usb stick? I chose a value of 1024, but isn't this going to create a load of extra writes to my USB stick for virtual memory?

Thanks
You can go with option #4 without worrying if you feel you don't need swap at all, although USB flash is not designed for heavy writing and are slow.

The (for expert) basically meant that you need to manually set/specify a swap partition on another drive, (mandatory in production environments)

If this is a home setup don't worry at all, if is a production setup, you'll probably use an SSD/small HDD overall.

Regards

Re: Enter the size of the swap partition in MB?

Posted: 14 Sep 2015 11:03
by F8BOE
Hello,

This is now a pretty old thread... Have things evolved since? Do we really need a SWAP partition at all when not using ZFS?

I find it pretty hefty for my CF card to be struggled day after day with read/write actions that will in the end only kill it!
On my PII 400 / 768 MB RAM, only 22% of the 727 MB left are used (max. at 28% when streaming videos for three users and audio for two users simultaneously) the SWAP keeps constant at 8% of the available 2GB on the CF.

OK, assuming there are no read/write actions as the SWAP used keeps constant (only assuming it...) I could live with it, but nonetheless, it's quite groovy to have this space filled up for nothing.

Since the new structure with SWAP etc... It takes four to five times longer to boot the server... Quite annoying...

So did people ever try to use their embedded system without SWAP on version 10.x? Did they encounter problems running the system without SWAP?

Ciao @+

Re: Enter the size of the swap partition in MB?

Posted: 14 Sep 2015 12:00
by Parkcomm
If you can keep the active processes within RAM you don't need swap - but the amount of memory required is based on numb er of programs, jails etc vying for mem space.

So if you don't run many programs you probably don't need swap (you can monitor with top or rrdgraphs)

Also you are right - don't put sap on your CF card, it will kill it. Put it on your data disks - if you can' provide a dedicated partition, swap can use a file.