alletra 5000 SNMP volume usage oid

[ThePayne]

Hello,

I'm trying to monitor via SNMP the volume usage. I get some numbers that should be bytes, but they are not even near the real usage.

root@myserver:~# snmpwalk -v2c -c community alletra-host 1.3.6.1.4.1.37447.1.2.1.6
iso.3.6.1.4.1.37447.1.2.1.6.0 = Gauge32: 650891
iso.3.6.1.4.1.37447.1.2.1.6.1 = Gauge32: 777199
iso.3.6.1.4.1.37447.1.2.1.6.2 = Gauge32: 3359177
iso.3.6.1.4.1.37447.1.2.1.6.3 = Gauge32: 16873706
root@myserver:~# snmpwalk -v2c -c community alletra-host 1.3.6.1.4.1.37447.1.2.1.7
iso.3.6.1.4.1.37447.1.2.1.7.0 = Gauge32: 0
iso.3.6.1.4.1.37447.1.2.1.7.1 = Gauge32: 0
iso.3.6.1.4.1.37447.1.2.1.7.2 = Gauge32: 0
iso.3.6.1.4.1.37447.1.2.1.7.3 = Gauge32: 0

First vol usage is 1.2 TB, secondo vol usage is 1.6 TB, third is 4TB, fourth is 18.5 TB. Also the total size shows something like 10MBytes
Anyone know how I should translate this to bytes?

[Satish04]

Hi ThePayne,

HPE Alletra storage array values are typically presented in blocks or units specific to the device, which may not directly represent bytes. This value needs to be converted to bytes based on the block size of the storage array.
HPE Alletra and other storage arrays use blocks or sectors as their basic unit of data storage. The SNMP values are often expressed in terms of these blocks, not bytes. You'll need to determine the block size before converting these values to bytes.
HPE support can usually provide you with this information or you can consult the storage array's documentation. It depends on how the array is configured whether the blocks are 512 bytes, 4 KB, or 8 KB.

Once you have the block size, you can convert the SNMP values to bytes using the following formula:

*Volume Size in Bytes = SNMP Value * Block Size*

You can convert SNMP values to bytes by determining the block size and using the conversion formula.
In case you are uncertain about the block size, I recommend contacting HPE Tesh support or consulting the HPE Alletra documentation.

Hope this helps.

Regards,
Satish

[ThePayne]

Hi Satish,

thank you very much for your answer. I hadn't thought of block size actually, and it's very interesting. I looked at the documentation of the MIB, and it says the value is bytes, but that in my experience is often wrong on the doc in general (all vendors), so I'll investigate the block size as you say.

What I can do fast is some math. The current usage of the first disk is 1.2TB and it shows 650891 via snmp.

1,200,000,000,000 / 650891 = 1843626

so block size should be around 2MBytes to match the numbers.

Also if I look at total size of volume instead of current usage, and I multiply for 2Mbytes blocksize:

10,000,000 * 2,000,000 = 20,000,000,000,000

I get 20TB, but the volume total size is 10TB only. So I think something doesn't add up: it doesn't look it's a constant missing.
Maybe higher bytes counter is somehow bugged? That should not be zero with TB disks I think...

I will also contact support as you suggested. Thanks again.

Regards