topic Re: va7100 raid 5 capacity in Disk Enclosures

va7100 raid 5 capacity

licong — Mon, 26 Aug 2002 06:47:58 GMT

my va7100 have 7*36G and 7*73G harddisk ,my va7100 raid 5 capacity ?

Re: va7100 raid 5 capacity

Vincent Farrugia — Mon, 26 Aug 2002 06:58:16 GMT

Hello,

First of all, VA7100 does NOT store in RAID 5, but in RAID 5DP, which, in theory, is RAID 6. With this, you can lose 2 disks and still have all LUN information intact.

Also, you CANNOT store RAID 5DP in a VA7100. You have to store it in AutoRAID, which is a combination of RAID 1+0 and RAID 5DP.

Having said that, it is very difficult to calculate the amount of data stored in RAID 5DP in any configuration possible. This is because the controllers put data in RAID 5DP intelligently themselves i.e. you cannot monitor how much data is actually in RAID 5DP. Only the controllers know the "controlled RAID mess" they created. :-)

HTH,
Vince

Re: va7100 raid 5 capacity

Joaquin Gil de Vergara — Mon, 26 Aug 2002 07:13:07 GMT

You can have 36 and 76 GB disk if you put in diferents RGs

Like Vincent says, VA is AUTO, it decides if use RAID 5DP or RAID0+1 (depends of total LUNs size, total disk space etc..)

Re: va7100 raid 5 capacity

licong — Mon, 26 Aug 2002 07:33:02 GMT

How by use the more 36G capacity in the 73G harddisk,where my va7100 have 7*36G and 7*73G harddisk.

Re: va7100 raid 5 capacity

Roger_22 — Mon, 26 Aug 2002 14:02:17 GMT

A VA7100 with 7 36GB and 7 73GB disks set in AutoRAID mode will have 529.95GB (decimal) usable capacity.

Re: va7100 raid 5 capacity

Tim D Fulford — Mon, 26 Aug 2002 15:13:46 GMT

Hi

1 - RAID 5 on the VA is marketed as RAID 5-DP, this is infact RAID6 (two parity blocks).

2 - I'm assuming 36GB disk format to 32GB & 73GB disks format to 69GB. so the calculation is
(7-2)* size
therefore 7x36GB ==> 5x32 = 160GB
and 7x72GB ==> 5x69 = 345GB

Regards

Tim

Re: va7100 raid 5 capacity

Roger_22 — Mon, 26 Aug 2002 17:26:35 GMT

Sorry, my previous answer was with one hot spare enable, no hot spare is 562.31GB decmial usable.

Re: va7100 raid 5 capacity

Roger_22 — Mon, 26 Aug 2002 17:33:50 GMT

Ok, I'm having problems typing. 1 hot spare is 496.42GB, no hot spare is 562.31GB -- both decmial numbers.