Helvick

12,492 reputation

11441

bio	website	helvick.blogspot.com
	location	Ireland
	age	47
visits	member for	3 years, 11 months
	seen	8 hours ago
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I'm an IT Systems Engineer with two decades of experience planning, building and managing IT Infrastructures ranging from small single office environments with a handful of users all the way up to global environments with 100k+ users.

I currently spend about half of my time in data center virtualization projects and half of my time developing and delivering virtualization and SAN training.

	12,492 reputation	bio	website	helvick.blogspot.com	visits	member for	3 years, 11 months
11441 badges		location	Ireland		seen	8 hours ago

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Dec 22	comment	What to storage to use? What do you mean by affordable - a general ballpark budget would be useful (<$5k, $10K, $100K). Affordable means very different things to different people. By "Ethernet for Data connection" do you mean iSCSI, NFS, CIFS, AOE, FCOE or something else? How many VM? Are you worried about resilience (you should be IMO but its your call)? RAID 0 - would you seriously use RAID 0 to host production VM's?
Dec 21	comment	Install 12x2 GB on dual socket mainboard with single CPU R710's? Single CPU with 12 DIMMs working?
Dec 21	comment	Maintenance window and recovery for a large database If the level of downtime necessary (and it is necessary) is genuinely unacceptable then someone has to pay to to either [a] redesign it from the ground up with a different approach that is less dependent on a solution that can take very long to restore or [b] pay to make it resilient as Tomtom stated. If the money\resources aren't there for either option then the reality is that a day (or more) of downtime is acceptable to the person making that call. Make sure the person standing over this makes that point to the whoever is controlling the purse strings.
Dec 21	comment	Why can't I create a RAID 1 on my 3ware 9650SE-4LPML? RAID 10 provides the same protection level as RAID 1, but the striping improves performance (well it should at any rate). Assuming it is a stripe of mirrors, which it should be.
Dec 21	comment	Slow Guest Boot on ESXi 4.1 Is this 32 or 64 bit CentOS? What is the ESXi box (type, #CPU Cores, RAM), what's the VM config (#vCPU's, RAM, no and type of NIC), what storage subsystem. Some possible ideas on things to look at in this VMware communities thread communities.vmware.com/thread/275561 , possibly unrelated but worth a look.
Dec 19	comment	What hardware raid cards are comparible to 3Ware (true separation between drive access and host CPU) Well Dell's PERC are LSI MegaRAID controllers and 3Ware is an LSI brand and as far as I'm aware LSI consider the 3Ware to be their cost effective value line and MegaRAID to be their performance line (for the most part) so I doubt that 3Ware will be a better option for you than PERC6.
Dec 19	comment	VMware ESXi 4.1 snapshot of server 2008R2 machine generates 2 indentical snapshots Can you list the files that you see in the Datastore Browser after you've taken a snapshot of one of the affected VM's.
Dec 19	comment	Wireless Client to Ethernet Bridge with Vyatta Have you tried using static IP's for the Vyatta appliance? Also it's been a while since I used Vyatta but I'm almost certain I had to define routes between the interfaces to get it to work.
Dec 19	comment	Where does ISP obtain their IP address from in order to connect to internet? 61 days to go .. (approximately) .. twitter.com/ipv4countdown
Dec 19	comment	RAID P410i and P812 performance issues Also when you say heavy sequential I/O is this predominantly Read or Write? And what sort of load are you talking about (both in terms of IOPs and, given that it's sequential, MB/sec)
Dec 18	comment	SAN over Ethernet I agree with most of what you are saying but any decent SAN hardware that supports iSCSI will support multiple front end ports and distribute IO loads across them with multi-pathing so iSCSI throughput is not limited to 1GBs even if your iSCSI network is only Gigabit Ethernet.
Dec 17	comment	LeftHand P4000 multi-site replication and vsa Do you really have a requirement for synchronous replication when you don''t have a resilient SAN in the first place? You do realise that synch rep will impact the performance of your production environment?
Dec 15	comment	IOps required to boot a KVM instance Just for reference the fairly small 16GB PAM modules referenced in this cost $15k each, and newer (but bigger ones) cost more. You'll hopefully be installing two as I'd hate to be running critical storage like this on non-redundant hardware and at a minimum the FAS 3170 configured to support this will come in at no less than $100k. Delivering 5x that performance will cost a lot more than 5x the cost of this example.
Dec 15	comment	Easy imaging with 1-to-1 virtualization You're correct there - the rebranding to vSphere Hypervisor hasn't been reflected across all the support docs yet but yes the limitation applies to the "free license" - the only license that enables >4-way vSMP is Enterprise Plus.
Dec 15	comment	vmware esxi linux guest optimization Some details on the ESXi host hardware and overall configuration (CPU, Memory, Network, Storage) would be useful additional information.
Dec 13	comment	Easy imaging with 1-to-1 virtualization @Charles \Josh - Sorry I wasn't clear - an unlicensed ESXi install will only support 4way vSMP, ie 4 virtual CPU's in the guest and so will only allow you to make full use of at most 4 cores if you are only virtualizing on a 1:1 basis. See here kb.vmware.com/selfservice/microsites/… . To enable more than 4way vSMP (up to 8way) requires Enterprise Plus licensing. This is a different issue to the No of Cores\CPU that are covered by a license - that used to be 4 for most versions and 8 for Enterprise, and is now 6 and 12 respectively.
Dec 13	comment	Easy imaging with 1-to-1 virtualization As I mentioned in my answer there are scenarios where the hardware abstraction is useful (try installing Windows 2000 on current gen Dell servers for example). Your reference to modern OS driver flexibility is accurate but not everyone can move everything to a more modern platform immediately. As far as backups are concerned I'd dispute the additional overhead. It might be, but only if you choose it to be. On attack surface the additional risk is not zero but it is low with ESXi. In terms of long term durability it has advantages, they are just not generally applicable and it is wasteful.
Dec 12	comment	Hostname doesn't resolve Likewise and I'm currently resolving that address to 129.21.125.240 via T-Mobile in The Netherlands so I'd guess that it's mostly OK. TTL is set to an hour so it should update reasonably quickly.
Dec 12	comment	Flow Control - Where do you enable it? The pnics are the ones that matter if you are delivering iSCSI storage to the vSphere hosts and they are set to auto however for the VM's that you are directly presenting storage to the native iSCSI you may need to use the e1000 vnic to provide flow control.
Dec 12	comment	HP Lefthand P4000 - Anyone got one? That's not quite true - Compellent use more or less commodity x86 servers too if I read their specs correctly. But the point is accurate - each node is a more or less standard server and all resilience requires multiple P4000's, and they will need a third node (usually a virtual appliance) to act as a failover manager if you only have two arrays.