Starwind Enterprise Caching. Good or bad?

[HelderConde]

Hi,

I'm just bought Starwind iSCSI Enterprise. I noticed that on the Windows Server 2008 x64 box in which I'm using it, I have all its 8 GB RAM being cached. I presume that's because Starwind is caching my iSCSI shares, so that the other machines can have quicker access to it. Am I right to think this way?

That same Windows Server 2008 box is being used as a file server (serving files via SMB, not iSCSI) to some other machines on the network.

My question is: since all RAM is being cached (possibly allocated to Starwind), won't my SMB sharing (or any other server activity) be affected? When other service on that machine request that RAM, will Starwind free some? Or, more specifically: won't this caching severely affect the performance of that box for other services other than Starwind?

Hope I'm making myself clear about this. Thanks in advance for your help!

Helder Conde

[anton (staff)]

If you're using StarWind to convert your legacy server into iSCSI appliance it's obvious you should leave ALL the resources to StarWind itself. All CPU cycles are going to be used for I/O processing, we'll turn all RAM turn into very effective write-back cache and all disk I/O should belong to StarWind itself (no swapping, no non-iSCSI disk seeks etc). In theory... But on practice in some cases people tend to keep other server side software co-existing with StarWind. In such a case we have a pretty classic interest conflict... In your case you should DEFINITELY limit StarWind's cache/RAM usage to 20-40% of the free physical memory. To avoid paging and machine slowed down on low memory resulted disk I/O. Turning write cache OFF does not make sense as well. It's going to do no good to you (unless you have other memory pigs on the same machine). The same is very true about network utilization. If you cannot allows yourself dedicated iSCSI server then at least throw some extra network card and route iSCSI traffic to the separate dedicated network...

Hi,

I'm just bought Starwind iSCSI Enterprise. I noticed that on the Windows Server 2008 x64 box in which I'm using it, I have all its 8 GB RAM being cached. I presume that's because Starwind is caching my iSCSI shares, so that the other machines can have quicker access to it. Am I right to think this way?

That same Windows Server 2008 box is being used as a file server (serving files via SMB, not iSCSI) to some other machines on the network.

My question is: since all RAM is being cached (possibly allocated to Starwind), won't my SMB sharing (or any other server activity) be affected? When other service on that machine request that RAM, will Starwind free some? Or, more specifically: won't this caching severely affect the performance of that box for other services other than Starwind?

Hope I'm making myself clear about this. Thanks in advance for your help!

Helder Conde