On 2022-10-06 4:54 PM, Dominique Bejean wrote:
Storage configuration is the second point that I would like to investigate in order to better share disk resources. Instead have one single RAID 6 volume, isn't it better to have one distinct not RAID volume per Solr node (if multiple Solr nodes are running on the server) or multiple not RAID volumes use by a single Solr JVM (if only one Solr node is running on the server) ?
The best option is to have the indexes in RAM cache. The 2nd best option is the 2-level cache w/ RAM + SSD -- that's what you get with ZFS, and you can use the cheaper HDDs for primary storage. The next one is all SSDs -- in that case RAID-1(0) may give you better read performance than a dedicated drive, but probably not enough to notice. There's very little point in going RAID-5 or 6 on SSDs.
In terms of performance RAID5/6 on HDDs is likely the worst option, and a single RAID6 volume is also the works option in terms of flexibility and maintenance. If your customer doesn't have money to fill those slots with SSDs, I'd probably go with one small SSD for system + swap, a 4-disk RAID-10, and a hot spare for it.
Dima
