On a new server I want to create a new virtual disk with writeback cache. The server has 3 physical disks, which is visible for the operating system as one, because it is in hardware-raid5 available. The operating system uses 140Gb of this disk. The server has a 120Gb SSD (unused). I now want to configure the rest of the available space of the harddisk for some partitions, using the SSD as writeback cache. To avoid, that just 1Gb is used as writeback cache, I have to use Powershell. So I have created a Storagepool, and dropped what is available in it. Then I used Powershel to create a SSDtier and HDDtier. As far as I can find, there is no option to specify sizes. The results are stored in $SSDtier and $HDDtier. Then I use Powershell to create a new virtiual disk. This is no success. After some trials with the syntax, the error now is: there are not enough eligible physical disks in the storage pool. The command I used is:
new-virtualdisk -StoragePoolFriendlyName "Pool1" -Friendlyname "Samen" -StorageTiers $SSDtier, $HDDtier -Storagetiersizes 10GB, 200Gb -Resiliencysettingname Simple -Writecachesize 50Gb
It would be better, if the 10Gb was 0Gb, but just to exclude this is part of the problem, I used these values.
The free size on SSDis 115G, and on the HDD is 490G
So what is wrong with this command?