Dell PERC S100 RAID Specs

Jared

Administrator
Staff member
I'm helping a guy remotely to recover a RAID 5 from a Dell Server using a PERC S100 controller (found model in metadata). Unfortunately it looks like someone initialized the drives and overwrote the partition tables. Anyone know what the default stripe size is on this controller? The manual appears that it's a left sync parity rotation, but no mention of stripe sizes.

Normally I'd just figure it out, but it's taking long because I have to scan each time due to the lost partitions.
 

jol

Member
Jared":21b0764w said:
[post]4376[/post] but no mention of stripe sizes
Code:
6.3.5 Stripe Size
Stripe size cannot be specified by user at create VD time. The stripe size is automatically set by the SW
RAID based on the total capacity and number of disks assigned to the virtual disk RAID levels.
https://www.dell.com/downloads/global/p ... _Paper.pdf

the same is here

Code:
Stripe size 		 Stripe size is determined by a PERC S100 adapter/PERC
                  S300 adapter algorithm. Stripe size cannot be configured by
                  the user.
 

Jared

Administrator
Staff member
Yes, I did come across that in my research. But, still never mentions any actual stripe "sizes", just the fact that the user can't configure it. I've already ruled out the possibility of it being smaller than 64K, but not sure if it might be bigger than that yet.
 

jol

Member
since the stripe size depends on total capacity and number of disks assigned, if the controller (PERC S100) is still working (and/or you have access to it), I would rather take the same no. of drives + same capacity, and build the RAID again, than trying to figure it out, and wasting long hours of scanning each configuration.
if it's not working or don't have access to it, maybe buying one is still worth it (didn't checked the price) ?!
 

Jared

Administrator
Staff member
Like I said, I'm helping someone remotely so not a case where I'm going to invest in buying a crappy old RAID controller or one where I have access to it. Would have been really easy too, if I just had a partition table to work with.
 

Jared

Administrator
Staff member
Finally beat this RAID. Right A-Sync parity rotation and 64Kb block size was the magic trick. Absolute last configuration I was going to try was the correct one. Doh! :roll:

Moving on to an EMC RAID for tomorrow now. :eek:
 

jol

Member
Jared":e1xm5rgs said:
[post]4392[/post] Right A-Sync parity rotation and 64Kb block size was the magic trick
since it has been made automatically depending on the size & no. of drives (as stated in the manual) would you mind telling us those details (if someone may come across the same situation) ?
 

Jared

Administrator
Staff member
It was three 500GB drives in RAID 5. My guess is that the controller just always uses 64KB block size and that "automatic" business is just a lot of bunk, but I don't have a way to test it.
 

jol

Member
Jared":29vuvkui said:
[post]4397[/post] It was three 500GB drives in RAID 5.
thanks
Jared":29vuvkui said:
[post]4397[/post] My guess is that the controller just always uses 64KB block size and that "automatic" business is just a lot of bunk
probably
 
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