NexentaStor - increasing swap space

Here's another tip I forgot to post yesterday. How to increase the swap space on your NexentaStor server.

When I was trouble shooting our NexentaStore server when it has low available drive space, in the NexentaStor documentation I found that the default swap size is the memory size. For some reason we had a 1 gig swap file, and 4 gig of ram. Perhaps we didn't have all the ram populated on original install, so just to make sure everything was setup correct to help my trouble shooting, I went looking for a way to increase the swap space.

Since there wasn't any option I could find in the web gui, I was certain it was going to be a CLI thang. After some googling, I came across this:

http://www.crypticide.com/dropsafe/article/2649

I ssh-ed into the NexentaStor server as the admin user, and ran:

zfs set volsize=4G syspool/swap

This changed the swap space to the same size as the physical ram in the server.

Comments

[fmp]

This didn't fixed my problem. setting the swap memory to 8GB (installed memory) has no difference at all. After 30mins in operation, swap memory has gone 250MB from "8GB". I monitored it using # swap -sh command.

I expanded the swap memory to 1.5 ratio, (12GB). It did the trick temporarily, but after approximately 2 hours - Nexentastor hanged again.

- no response in ssh
- no response through the physical keyboard

Am really frustrated, on how to find those missing memory allocation - Am sure there is memory leak somewhere and this certainly is a Nexentastor Bug!

I will add 8GB memory to the server, let's see what happens. I'll keep you posted.

[fmp]

Finally, I've upgraded the memory to 16GB and everything works intact. Except for Nexentastor! there's a transparent Memory Leak. See details below:

Monitoring swap space:
- http://pastie.org/2984241

and then compare it with:

prstat / top command in opensolaris / Nexentastor
- http://pastie.org/2984257

See the big difference!

Available memory is: 12GB
Used memory is: 1.6GB
It displays 9.7GB available memory
Now where the heck is 700MB of memory gone!? this is a huge cache that can be utilized by the server.

- fmp

[fmp]

still my production service hanged after 7 hours.!!!
Nexentastor is not a to be trusted system for production.

-fmp