Tag Archives: Tool

Determine TBW from SSDs with S.M.A.R.T Values in ESXi (smartctl)

smartctl-in-esxiSolid-State-Drives are getting more and more common in ESXi Hosts. They are used for caching (vFlash Read Cache, PernixData FVP), Virtual SAN or plain Datastores. A problem that comes with SSDs is their limited lifetime per cell. Depending on their technology, each cell can be overwritten from 1.000 times in consumer TLC SSDs up to 100.000 times in enterprise SLC based SSDs.

The value to keep an eye on is the guaranteed TBW (Total Bytes Written or Terabytes Written) which is typically provided by the vendor in their specifications. This value describes how many Terabytes can be written to the entire device, until the warranty expires. The current value can be readout with S.M.A.R.T. in the Total_LBAs_Written field.

Unfortunatelly, VMware makes it hard to readout RAW S.M.A.R.T values on ESXi hosts. For that reason I've ported a version of smartctl, which is part of  smartmontools to ESXi. I've made the package available as VIB. The download link is at the bottom of this post.

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New Tool: Decoder for ESXi SCSI Sense Codes

scsi-sense-codeI've published a new tool that helps to quickly decode SCSI error codes displayed in vmkernel.log when something gone wrong. The tool uses an internal database to translates SCSI codes to human readable status information.

VMware ESXi SCSI Sense Code Decoder

Please do not hesitate to comment when there are any questions, or you've encountered an error with the decoder.

How does it work? Let's assume that your vmkernel.log shows the following error mesage:

2011-04-04T21:07:30.257Z cpu2:2050)ScsiDeviceIO: 2315: Cmd(0x4124003edb00) 0x12, CmdSN 0x51 to dev "naa.[...]" failed H:0x0 D:0x2 P:0x0 Valid sense data: 0x5 0x24 0x0.

Simply enter the colored hexadecimal numbers to the form and press Submit:
scsi-sense-decoder-howto

The result and a short description is displayed:
scsi-sense-decoder-result

When you've entered all information, you can copy the URL for future reference. You can find the above example here.

New Free Tool: VMware Software Manager

Together with vSphere 6.0, VMware released a new free tool that simplifies the download of VMware suites and products. The tool is very simple, its totally worth giving it a try. Install it on your desktop, login with your My VMware account and download all products and features of a VMware Suite with on button.

Software Manager Download Page

This is how it looks like:
VMware-Software-Manager-website

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