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bio website linkedin.com/in/dyasny
location Canada
age 34
visits member for 5 years, 5 months
seen 22 hours ago

Open source virt geek


Nov
10
answered High packet loss with kvm, bridge and bonding
Nov
6
comment Is the gang scheduling employed by VMware a serious drawback?
So, if I install single-threaded (duh!) MSDOS in a 16-core VM, every CPU cycle of the VM will not lock down 16 cores on the host, but only one pCPU? This, and not the speed of CPUs, is the main drawback of gang scheduling.
Nov
4
comment Guest-VM can only ping CentOS KVM host, cannot access anything else
Any chance the switch has port protection turned on, and it blocks traffic originated at a MAC that isn't the MAC of the plugged in eth?
Nov
3
comment Change KVM boot order with multiple virtio disks in guest
you've got it :)
Nov
3
answered Change KVM boot order with multiple virtio disks in guest
Nov
2
comment Change KVM boot order with multiple virtio disks in guest
well, it obvious, set the wanted disk as virtio-disk0, with target of /dev/vda. The order the disks appear in, in the XML are also important, so make sure the OS disk comes first
Nov
2
comment Change KVM boot order with multiple virtio disks in guest
Please post the domxml and which disk you want to be first
Oct
28
awarded  Nice Answer
Oct
28
comment Can't access KVM Host (network brige)
the configuration looks fine, maybe there's an IP conflict on the network or some other related issue
Oct
27
comment Best way to clean up Yum repository?
great stuff, wasn't aware of this one
Oct
25
comment What should an Ops person know about hardware for an interview?
usually drives that get kicked out of an array, while remaining usable have bad firmware (or the controller does). bad blocks get relocated until there is no more room to relocate, and then the drive becomes physically faulty. bad firmware often causes scsi timeouts, which in turn cause the disk to fail to respond in an array, and get marked as faulty
Oct
25
comment What should an Ops person know about hardware for an interview?
I was walking about TWO failed disks, not one. The idea of retagging is to bring the array up with only one disk missing, which is tolerable. The main trick is to know which of the two failed disks to keep
Oct
25
answered How can I tell Linux to ignore disk partitions it's already discovered?
Oct
25
comment What should an Ops person know about hardware for an interview?
It's a well known procedure called retagging. With two failed disks, you can't backup the data, but you can look at the logs, find out which drive failed first, and build a new array, focing the first failed disk offline. Always a good chance to get accessible data in a degraded array - good enough to slavage what needs to be salvaged
Oct
24
comment What should an Ops person know about hardware for an interview?
ask them what they would do with a raid 5 in which two drives failed, within a day of each other. Both drives are still usable, and will not be replaced
Oct
23
answered Ovirt Manual Start Up
Oct
20
comment Infiniband + KVM
I know for certain IPoIB setups with KVM work quite well, Mellanox have showcased quite a few use cases. IIRC, most of those were simple L2 bridges over an IB interface, with virtio_net in the guest.
Oct
17
answered vCPU performance between 1 or 2 vCPU's
Oct
16
answered How to connect SAN from CentOS through two iSCSI Targets
Oct
11
comment Are /dev/disk/by-id symlinks unreliable?
if you're provisioning in a VM (is this TripleO?) the disk IDs may not be reliable, but under KVM the disks always show up in the sam eorder they are defined in the libvirt domxml. On real hardware, these IDs should be reliable afaik.