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SebastiaNet
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"Add Storage" only sees 185 GB instead of 8,18 TB

Hi. We are using ESX 4.0 on a x3850-M2. Have some internal disc (400 GB), one external DS3400 (500 GB), then a DS3000 extension (800 GB) and another new DS3400 (3 times 1,64 TB).

The x3850 has a Brocade fibre channel to a SAN-24 switch where all the DS3400 and V3700 meet.

Now we buy another V3700 storage (8 TB), and connect it to the SAN-24 (configured properly)

ESX sees the Fibre Channel Device, detects OK that it has a capacity of 8 TB ... but allows me to create only a 185 GB volume.

I have found that VMFS has a 2 TB limit, and we shall use "extensions" to it, but ... where does the 185 GB limit come from ?

Please, have a look at the attached PNG file where a nice print screen displays all the details ...

Thanks for any idea. Sebastian.

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weinstein5
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Yes you will have to split the 36 TB into 2 TB LUNs - but remember the - 512B so slightly smaller than the 2 TB -

I am not sure were the 185 GB comes form but I have always seen this how the vmkernel reports a LUN when it is too large - this goes back to the days of ESX 2.x -

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weinstein5
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The ESX/ESXi 4 limit also applies to the maximum LUN size  - they cannot use LUNs larger than 2 TB -512 B and the 185 GB comes from its inability to see the 8 TB -to use the 8 TB you will have to -carve up into 4 LUNs - you will then need to format the first LUN as VMFS and add the remaining 3 as extents - if you want to use an 8 TB LUN as a single data store you will have to upgrade to vSphere

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SebastiaNet
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Hi - in fact, the V3700 has 12 discs of 3 TB each.

I have created 3 partitions using RAID-5 all of them, so I end up with 3 partitions of 8,2 TB.

One of those is made available to my ESX.

Do you mean I have to split the 36 TB into 2 TB LUN's or partitions ?

===================================================

We are OK with ESX 4.0 and can not go to vSphere.

Thanks. Sebastian.

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SebastiaNet
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in /var/log/vmkernel file I find ...

===

Feb  3 15:45:51 bcnlab003 vmkernel: 111:05:58:45.449 cpu12:4212)

WARNING: ScsiDeviceIO: 1462:

Device 'naa.6005076  30080835d6000000000000000':

Capacity (numBlocks=0x417200000) exceeds maximum supported device size of 2TB - 512   Bytes

===

... which seems OK to me -

Still a question : where does 185 GB comes from ????

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SebastiaNet
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another interesting message :

===

# dmesg

[9350545.355336]   Vendor: IBM       Model: 2145              Rev: 0000

[9350545.355428]   Type:   Direct-Access                

     ANSI SCSI revision: 06
[9350545.357290] sdh : very big device. try to use READ CAPACITY(16).
[9350545.357529] SCSI device sdh: 17179869184 512-byte hdwr sectors (8796093 MB)
[9350545.357744] sdh: Write Protect is off
[9350545.357759] sdh: Mode Sense: 97 00 10 08
[9350545.358136] SCSI device sdh: drive cache: write through w/ FUA
[9350545.358461] sdh : very big device. try to use READ CAPACITY(16).
[9350545.358599] SCSI device sdh: 17179869184 512-byte hdwr sectors (8796093 MB)   <<<<<<<<<<<<<<<< this looks like 8 TB to me ........
[9350545.358739] sdh: Write Protect is off
[9350545.358754] sdh: Mode Sense: 97 00 10 08
[9350545.358981] SCSI device sdh: drive cache: write through w/ FUA
[9350545.359006]  sdh: unknown partition table
[9350545.359227] sd 5:0:9:0: Attached scsi disk sdh
[9350545.359302] sd 5:0:9:0: Attached scsi generic sg10 type 0

===

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weinstein5
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Yes you will have to split the 36 TB into 2 TB LUNs - but remember the - 512B so slightly smaller than the 2 TB -

I am not sure were the 185 GB comes form but I have always seen this how the vmkernel reports a LUN when it is too large - this goes back to the days of ESX 2.x -

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SebastiaNet
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thank you, mr WeinStein - I have done a 1,98 TB LU and the ESX sees it OK and wants to provide a 1,98 TB disk to my VMs (see attached pic)

Cheers !

v3700_2TB_limit.PNG

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SebastiaNet
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do you think it is a ESX v4 limitation and shall be removed/improved in ESX v5 ?

Sebastian

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weinstein5
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Yes it is an ESXi 4 limitation - if you check in the configuration maximum document (https://www.vmware.com/pdf/vsphere5/r55/vsphere-55-configuration-maximums.pdf) under ESXi Host Storage maximums you will see that ESXi now supports LUNs up to 64 TB in size -

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