Batteries for hardware RAID controllers are the worst... and they're not hot-swappable.
Hardware RAID Controllers are the worst
@Vamp898 no, the battery is worse than the controller.
If you manage to configure the controller properly, it will work just fine as long as you don't touch anything.
But the battery? It will wear out even if you don't have power outages. And then it will fail, causing the controller to disable cache and hammer your disks.
So it's the battery that can suddenly ruin your day in the middle of holiday break, not the controller.
Now, if the batteries were hot-swappable, they wouldn't be that bad. They could even be better than the controllers. But they are not hot-swappable.
I never liked hardware raid controllers, they are bad in so many ways hard to describe.
I stopped using them in 2012 and never had any RAID issues anymore since then
were you by chance the person from whom Polish Olympiad in Informatics bought that second-hand PowerEdge R710 ?
@Vamp898 yeah if I were doing a fresh OS install on a server, I'd flash the HBA firmware (so called "IT mode") onto the RAID controller, and use mdraid or LVM raid all the way down. Way more flexible.
And more stable/robust
WARNING: Controller0=Ok/Ready [ Battery0=Non-Critical/Degraded ]
maybe it's just a learn cycle tho...
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