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LSI megaraid single drive raid0 or jbod write back or through cache enabled yadayada
playing with a server that has an LSI SAS 3108 raid card.
so far i've been "creating virtual drive" for one drive installed which is raid0. then i want to add a 2nd drive and have it mounted in linux as /scratch for example so i do the same thing create virtual drive on that.
this raid card supports jbod.
when virtual drive is created i can go into advanced menu and set it to either write back or write through. I have no battery backup unit on the raid card. Internet seems to say write back gives better performance than write through however can be risky if power goes out suddenly. i can also choose either direct or cached for each drive option. and there was maybe 1 or 2 other options.
when the drive is set to jbod, i can't access any of that advanced stuff in the menu.
by setting just a single drive installed in my server to jbod do i lose any read/write performance compared to having it set as virtual drive raid 0?
the drive is a 300 or 600 gb SAS 2.5" seagate savio.
does AHCI apply to SAS hard drives and connections, or is that just on SATA?
when i don't want multiple drives grouped together purposely for a raid volume of 1+ terabytes, i do want the ability of hot swapping drives which seems to not work when they are either not configured in the menu beforehand or are previously configured as a raid0 virtual drive. in this case i have to reboot and Ctrl-R and get it to recognize. if i take the time which a bunch of spare drives that i want to be hot swappable should i set them to JBOD in the raid menu or would i be wasting my time?
Last edited by ron7000; 09-02-2015 at 09:18 PM.
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