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location Italy
age 41
visits member for 3 years, 6 months
seen 2 days ago

Sysadmin, postmaster and later Perl developer


Sep
24
awarded  Autobiographer
Jan
11
comment Is there any chance to get Hyper-V enlightened I/O inside Windows 2008 R2 recovery DVD?
I agree. My poor understanding of what is really going on under the hood is the real bottleneck here. I did also another test, a bare metal restore using Hyper-V 2012 hypervisor, with the same hardware and guess what! Again 55 Mbit/s read speed from iSCSI. I have to do some more RTFM on the subject. Does the 4k sector issue have something to do with my case?
Jan
11
comment Is there any chance to get Hyper-V enlightened I/O inside Windows 2008 R2 recovery DVD?
I opened perfmon during restore phase in Hyper-V server. Virtual disks are on drive D: ( disc 0 ), so I measured avg. write queue length for logical drive D:, and avg. read queue length for physical disc 1 ( iSCSI target ). In a scale of 100,0, I got a steady line around 90 for the write queue length, and values in the 20-30 range for the read queue length. I'd look for other performance objects, but being a real noob in the field of Windows, it will take some time to choose the right ones...
Jan
10
comment Is there any chance to get Hyper-V enlightened I/O inside Windows 2008 R2 recovery DVD?
I did it but it wasn't required, given the recovery setup: the Hyper-V server is connected with an iSCSI target, which was the drive used for backups; that drive is offline on Hyper-V server ( diskpart.exe ) and is connected directly to the virtual machine SCSI controller, as a SCSI virtual disk. This recovery setup is designed to bypass the network stack entirely, with a fast media ( virtual SCSI is faster than virtual IDE ) to read from. Why is it so slow to get data even from a "local" virtual SCSI drive? Does poor write speed to IDE show itself as slow read from SCSI?
Jan
10
comment Is there any chance to get Hyper-V enlightened I/O inside Windows 2008 R2 recovery DVD?
You headed me in the right direction. I managed to get cab files inside vmguest.iso on Hyper-V host; after a successful driver injection into boot.wim I made a fresh install ISO DVD using oscdimg.exe. Services like storflt, storvsc, vmbus and vmbushid are running, but still I can't get past 55 Mbit/s treshold... What am I doing wrong?
Jan
9
awarded  Supporter
Jan
9
awarded  Student
Jan
9
asked Is there any chance to get Hyper-V enlightened I/O inside Windows 2008 R2 recovery DVD?