VA 7100 configurations.

[Hanry Zhou]

Questions:

1. How can I estimate the available usage withing the array? AutoRaid cannot stick a particular one level of raids, so how do I know how much total of capacity I can use withing 10x73gb space?

2. How do I figour out which devicefile is belong to Primary, which one is to Secondary controller?


3. I have following format of the devicefile:
c8t[0-3]d[0-7]
c10t[0-3]d[0-7]
Can you please tell me what the number stands for after the letter "t", and "d"?

4. I have HP08 firmware revision on disk modules. Is it too out of updated? firmware revision on controller is HP18, which is ok I believe.

Thanks,

[Eugeny Brychkov · Accepted solution]

4. if these disks are 405FC then HP08 is the latest;
3. c is a card instance (see this number under ext_bus entry; t and d for SAN devices are LUN identifiers. Array's LUN#=t*8+d. example: c8t1d5 - card 8, LUN=1*8+5=13 (LUN #13);
2. by switch port number or loop-id (in case of private loop). Example:
0/4/0/0.1.17.0.0.1.5
switch domain id =1
port #1 (1GB/s brocade, 16+1)
fabric (0)
1. tell me your requirements, I will calculate all you want
Eugeny

[Hanry Zhou]

Eugen, you are the best here!

2. by switch port number or loop-id (in case of private loop). Example:
0/4/0/0.1.17.0.0.1.5
switch domain id =1
port #1 (1GB/s brocade, 16+1)
fabric (0)

Can you explore it a little bit more? Which field is switch domain, port number, and fabric number withing 0/4/0/0.1.17.0.0.1.5 ?

1. tell me your requirements, I will calculate all you want

I have 10 disks with 73G each, so I configure the array to AutoRaid, can I tell how much usable space I can have?

5. Also, how can I configure the spare one in case one of module failed? Currently it is configured as "automatic" how would that work?

Thanks,

[Eugeny Brychkov]

2. path to the device looks like
hwpath.a.b.c.x.y.z
- hwpath is a hardware path where FC card is installed (internal to server, may vary in length);
- a, b, c - SAN path to the 'box' (within which LUN is created): a - switch domain ID (8 in case of private loop), b - port ID (0 for private loop, port number for 2G brocades and 0x10+port number for 1G brocades), c - loop-id (0 for fabric);
- x, y, z - LUN identifiers: LUN#=z+8*y+128*x.

1. with active hotspare (AHS) you'll get 468GB, without AHS - 534GB;

5. for hotspare settings explanations please look through user and service manual located at http://h20000.www2.hp.com/bizsupport/TechSupport/DocumentIndex.jsp?contentType=SupportManual&docIndexId=3124&locale=en_US&prodSeriesId=89018&prodTypeId=12169 , page 57
Eugeny

[Hanry Zhou]

Thank you very much for the message.

Now I have only one question left with regards the usable capacity of the array.

1. with active hotspare (AHS) you'll get 468GB, without AHS - 534GB;

How did you figure out these two numbers?

I have read the document(p.g. 57) you are referring to, but still cannot figour it out by myself:

A). The section on page 57 for VA 7400 only, but I have VA 7100.

B). The whole section did not mention how to calcuate the capacity in both case of with and without AHS.

Thanks,

[Hanry Zhou]

Hello, Eugen?

[Tim D Fulford]

I have not used a VA7100, only VA74x0. I believe they are very similar... If you use "armdsp -a " there is a section called "CAPACITY USAGE" In here it will list what is available for what.

On a planning side the unformatted & formatted sizes are roughly
18GB ~ 16.0GB
36GB ~ 32.5GB
73GB ~ 66.0GB
How you work out the formatted:unformatted space I do not know, I just know these figures!!

So if you have 10x73 GB disks there is really 10x66GB of usable space on each disk.

RAID5DP requires 2 parity blocks per stripe (2 disks) thus 8x66GB will be usable. If you require a hot spare this will then drop to 7x66GB. [528GB, 462GB]

RAID1+0. This is simple mirroring, thus if you just do RAID1+0 then it will be 5x66GB is usable. If you want to have a hot spare, because it is RAID1+0 you actually will use two, so then 4x66GB. [330GB, 264GB]

AutoRAID. this is a mixture of the above, the aray decides on how to split the RAID5DP & RAID1+0 up.

As far as the disk names, "t" stands for targit ID (on straight SCSI disks it is the SCSI ID) and d is the logical unit assigned by the LUN. Thus c8t[0-3]d[0-7] can deal with 32 LUNs

I'm not 100% sure about your firmware as it will vary with the disks. we have ST373405FC and are using HP04.

Regards

Tim

[Eugeny Brychkov]

Yes, I'm here. I think VA7400 rules apply to VA7100 also. I do not know algorithm how to calculate VA usable capacity (Tim's can be used to calculate capacity approximately). It depends on many reasons: how long stripe is and where image/map disks are.
Maybe someone will reply who knows how to calculate exact capacity or has a link to the tool which does it
Eugeny