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Server 2012 R2 VMs in ESXi on SSD backed Starwind iSCSI LUNS
Posted: Fri Jul 31, 2015 3:17 am
by Trevbot
I am noticing that the VMs do not recognize their virtual disks as SSD. In addition, ESXi (5.5 fully patched) does not recognize the iSCSI LUN as SSD either. Is this by design? I ask because I also notice the automatic maintenance task that runs by default on the Server 2012 R2 VMs appears to be defragging the virtual disk since it is not recognized as SSD storage.
Re: Server 2012 R2 VMs in ESXi on SSD backed Starwind iSCSI LUNS
Posted: Mon Aug 03, 2015 9:58 am
by Jhon_Smith
Hello!
Are you using any RAID for those SSDs?
Have you checked if your SSDs are supported by VMware?
Re: Server 2012 R2 VMs in ESXi on SSD backed Starwind iSCSI LUNS
Posted: Mon Aug 03, 2015 6:48 pm
by Trevbot
Storage and Compute separated. The SW SAN consists of SSDs that are connected via LSI9211-8i in IT mode (No raid) and while the OS that SW is running on (Server 2012) recognizes the SSDs correctly, the ESXi host connecting to them via iSCSI does not. Even when the SSD are directly connected to the MB on the SW machine, its the same issue.
Re: Server 2012 R2 VMs in ESXi on SSD backed Starwind iSCSI LUNS
Posted: Wed Aug 05, 2015 5:38 pm
by darklight
Re: Server 2012 R2 VMs in ESXi on SSD backed Starwind iSCSI LUNS
Posted: Sat Aug 08, 2015 1:36 am
by Trevbot
Not using HA and the ESXi host(s) can connect to the LUNs just fine, they just do not see them as SSD and as such, neither do the VMs stored on the LUN.
Re: Server 2012 R2 VMs in ESXi on SSD backed Starwind iSCSI LUNS
Posted: Mon Aug 10, 2015 12:59 pm
by darklight
Yeah, that is the way how free version works now i believe. You have to use NFS storage on top of StarWind device to be able to present it to your ESX environment.
Re: Server 2012 R2 VMs in ESXi on SSD backed Starwind iSCSI LUNS
Posted: Thu Aug 13, 2015 9:59 am
by Vladislav (Staff)
Hi Trevbot,
Regarding your initial question about SSD recognition:
Unfortunately, current StarWind release represents SSDs as HDDs via iSCSI. The fix will be on board in a month or two.
Re: Server 2012 R2 VMs in ESXi on SSD backed Starwind iSCSI LUNS
Posted: Fri Aug 14, 2015 6:55 am
by Delo123
Maybe you can simply force esxi to see the luns as ssd. they will be marked as ssd in vsphere...
# esxcli storage nmp satp rule add --satp=SATP_TYPE --device eui.80d6xxxxxxxx --option "enable_ssd"
or force all starwind luns
# esxcli storage nmp satp rule add --satp VMW_SATP_ALUA --vendor "starwind" --option "enable_ssd"
Re: Server 2012 R2 VMs in ESXi on SSD backed Starwind iSCSI LUNS
Posted: Fri Aug 14, 2015 10:30 am
by Vladislav (Staff)
If it possible, then yes, it is a good choice. StarWind knows all SSD specific commands like TRIM and successfully deals with them.
Thanks Delo123
Re: Server 2012 R2 VMs in ESXi on SSD backed Starwind iSCSI LUNS
Posted: Sat Oct 17, 2015 9:11 pm
by Trevbot
Well, good news and bad news. Good news is a modified version of that command with a different claim rule for specific devices (don't use --vendor "starwind" if you have any HDD backed devices as this will cause them to stop responding) will claim the device as SSD after rebooting the host (command needed to be run on each host). Bad news is that the VMs created when SSD backed LUNs were claimed as an HDD still report they are on HDD storage. VMs created after report as SSD. That being said, the VMs should "optimize" rather than "defrag" the drive but reports "Optimization not available." Not a big deal and pretty much expected. Will attempt a few other things to see if previously created VMs can be made to report as SSD.
Re: Server 2012 R2 VMs in ESXi on SSD backed Starwind iSCSI LUNS
Posted: Mon Oct 19, 2015 12:46 pm
by nohope
Hello,
I've already noticed such behavior using other ISCSI server providers. Not sure if it's starwind related issue, looks more like ISCSI protocol limitation. However, it's never been critical for me. There is no impact in performance at all, so I don't see anything you have to worry about. In addition, you are able to mark "SCSI-HDD" device as "Flash" in VMware web-client (vSphere 6.0 supports it for sure).
P.S. The only impact, described in VMware KB article, of SSD ISCSI device presented as "HDD" is not being able to use It for host cache

Re: Server 2012 R2 VMs in ESXi on SSD backed Starwind iSCSI LUNS
Posted: Thu Nov 05, 2015 10:06 pm
by Vladislav (Staff)
nohope, thank you for your help
Trevbot, do you have any other questions?