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Best Practice for caching in a single node iSCSI SAN

Posted: Tue May 03, 2016 3:57 am
by RyanNW
Hello Guys,

I have just setup a single node StarWind Virtual SAN free. I have got 64GB RAM, several SSDs, and a pool of 7.2K spinning disk.
I have set write-back mode for L1 cache and write-through mode for L2 cache. The performance was excellent.
However, as far as I understand, we shall not use write-back mode for L1 cache for single node since there might be chances of data corruption during power outage. I then created another device with write-through L1 cache. The performance is much much slower than the write-back mode.

Is there any special way for boosting the performance for a single node SAN while keeping the data safe?

Thanks in advance.

Re: Best Practice for caching in a single node iSCSI SAN

Posted: Wed May 04, 2016 11:00 am
by Dmitry (staff)
Hello Ryan,
In case of single device you need to split the difference about best performance and better data safety.
You are quite right, you need to use WT mode for L1 cache.
But you can try trial version and use HA device with WB cache mode. (If you have two server nodes for vSAN)
In this instance, you have two live copies of your production.

Re: Best Practice for caching in a single node iSCSI SAN

Posted: Thu May 05, 2016 3:07 am
by RyanNW
I see.
Thanks a lot.

Re: Best Practice for caching in a single node iSCSI SAN

Posted: Fri May 06, 2016 11:24 am
by Oles (staff)
Please let us know if you have any questions left.

Have a great day!