What constitutes 'fake raid'? (curiosity)

Issues related to hardware problems
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lightman47
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What constitutes 'fake raid'? (curiosity)

Post by lightman47 » 2018/07/25 19:08:37

How does one know, prior to buying or even just installing, whether they have or are buying fake raid? What should be looked for? How can we easily tell?

In my personal case, my Proliant room heater (DL380 G5) is running raid 10 (1+0) which was achieved by installing a couple "hp{something}" switches into the startup line both during install, and into my fstab. Is mine fake raid?

Thank you.

hunter86_bg
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Re: What constitutes 'fake raid'? (curiosity)

Post by hunter86_bg » 2018/07/26 12:45:20

In your case you need to use the hpacucli (CentOS6) or hpssacli (CentOS7) for the raid battery status.

Usually fake raids require some extra drivers during installation and they lack a cache battery.
Failed fake raid requires the same motherboard to restore data, while using the CPU just like software raid.

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TrevorH
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Re: What constitutes 'fake raid'? (curiosity)

Post by TrevorH » 2018/07/26 13:34:02

FakeRAID has all its intelligence in the drivers on the host system and uses the host cpu for RAID caluclations. Hardware RAID has all this in hardware. In addition, hardware RAID will often have cache RAM on board and a battery/capacitor to keep any unwritten data alive until it can be written to disk in the event of a power failure.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

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