VMware Virtual Storage Appliance Overview
In one of the comments on my post about the new vSphere 5 functionality, Omnimod's colleague was skeptical about the Virtual Storage Appliance (VSA). Frankly speaking, I myself was very interested in this new functionality and therefore I decided to make sure how skepticism of a more experienced comrade is justified.
So let's take a quick walk through VSA.
The main goal of VSA is to provide SMB companies with full functionality of publicly available NFS storage using local ESXi host disks. That is, using VSA in a remote office, with 2-3 ESXi hosts, you will not need to buy a NAS or SAN.
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This is what VSA looks like when installed on 3 hosts.
In a two-host scenario, your vCenter will emulate the third VSA node, which will play the role of quorum in the event of a drop in one of the nodes. This should help avoid split-brain problems, in which theoretically you can get two copies of your virtual machine running on different nodes, which unfortunately have lost contact with each other.
Using shared storage with VSA you get the opportunity to enjoy all the corresponding bonuses in the form of HA and DRS cluster, vMotion, Fault Tolerance. Yes, in vSphere 5, as you remember, FT is supported on the NFS datastore.
Data protection is provided by the use of RAID-10 on local disks and RAID-1 - between VSA storage cluster nodes. In VSA version 1.0, 3 hosts are currently supported, but all other hosts of your data center can easily use VSA storage. You can use no more than one VSA cluster on one vCenter.
Before you start the VSA installation, you should carefully evaluate your requests for disk space and the appropriate number of hard drives required. It should be borne in mind that in the end you will get 25% of usable usable space of the total disk space. I think it would be great if in the next VSA releases we were given the opportunity to choose a local type of RAID. The performance of a disk system is not always critical and therefore in some cases I would prefer to use RAID-5 locally in order to reduce overhead. According to the latest data, VSA will work with any local RAID, but support will apply only to RAID-10. Once you have completed the installation and configuration you can no longer add disks or resize your NFS datastore.
The installation procedure is very simple. First you install the VSA Manager, which later installs its plugin into the vSphere Client. When you connect to your vCenter, you simply run the VSA Wizard, which will help you determine the list of ESXi hosts that meet the VSA requirements. After that, a VSA virtual machine will be installed on each of the selected hosts, and then the wizard will help you easily and quickly raise vMotion between VSA nodes, enable HA and DRS.
On each of the VSA nodes, two disk volumes will be created: the first will be used under the NFS datastore, and the second will be used to store the NFS Datastore replica from one neighboring node. In principle, the first picture shows it well. Those VSA virtual machines that have been installed on the VSA cluster nodes will perform the following functions:
Once you have completed the installation, you get a fully resilient and accessible storage system without a single point of failure.
Using VSA you are protected at once on several levels:
VMware officially announces 99.9% availability of your virtual machines with properly configured VSA and HA.
I, alas, could not find deeper technical details, and the demo version of vSphere 5 is still available only to the select. Therefore, I switched to the financial side and tried to calculate the approximate cost of such a solution for a small or remote office. I relied on the prices that I gave me to Google and that are adequate to my region (Italy). Therefore, they can be very different from your prices, possible discounts and from your ideas what should be vSphere in a small office.
In my ideal remote office, I would have 3 HP Proliant DL380 G7 servers, in each of which I would place 6x600GB 10K disks. In its pure form, it would give me 10.8 TB. Considering all the RAIDs of usable space, we will have 2.7 TB, in three NFS storages of 900 GB each. Yes, as it seems to me that this is a big loss of disk space. And that's why I immediately thought about local RAID-5.
But on the other hand, let's all start from the price of one gigabyte for a completely redundant shared storage.
It was here that I found that the disks I needed would cost 368 euros, which would result in 6,624 euros for 18 disks. The announced price is VSA $ 5595, I think in Europe there will be the same figure, but in euros. Total we have 6624 + 5995 = 12,619 euros. We divide this figure by 2700 GB and get 4.67 euros per one gigabyte . I find it difficult to estimate expensive or cheap, so I would be very grateful if you could leave in the comments the names of competing VSA products and their cost per GB in your companies.
I assume that there are products that are cheaper, but there are also generally free ones, like Openfiler or FreeNAS. However, I would like to give some quite serious arguments in favor of VSA:
The only disadvantage of VSA at the moment is the high loss of disk space for protecting virtual machines, but as I said earlier, you need to focus on the cost of a gigabyte, which essentially should include not only the net cost of the disks and the redundancy provided, as well as operating expenses, which may consist of elapsed time, backup systems, support costs, etc.
As usual, any comments with valid criticism, additions, corrections of inaccuracies are welcome.
So let's take a quick walk through VSA.
The main goal of VSA is to provide SMB companies with full functionality of publicly available NFS storage using local ESXi host disks. That is, using VSA in a remote office, with 2-3 ESXi hosts, you will not need to buy a NAS or SAN.
')
This is what VSA looks like when installed on 3 hosts.
In a two-host scenario, your vCenter will emulate the third VSA node, which will play the role of quorum in the event of a drop in one of the nodes. This should help avoid split-brain problems, in which theoretically you can get two copies of your virtual machine running on different nodes, which unfortunately have lost contact with each other.
Using shared storage with VSA you get the opportunity to enjoy all the corresponding bonuses in the form of HA and DRS cluster, vMotion, Fault Tolerance. Yes, in vSphere 5, as you remember, FT is supported on the NFS datastore.
Data protection is provided by the use of RAID-10 on local disks and RAID-1 - between VSA storage cluster nodes. In VSA version 1.0, 3 hosts are currently supported, but all other hosts of your data center can easily use VSA storage. You can use no more than one VSA cluster on one vCenter.
Before you start the VSA installation, you should carefully evaluate your requests for disk space and the appropriate number of hard drives required. It should be borne in mind that in the end you will get 25% of usable usable space of the total disk space. I think it would be great if in the next VSA releases we were given the opportunity to choose a local type of RAID. The performance of a disk system is not always critical and therefore in some cases I would prefer to use RAID-5 locally in order to reduce overhead. According to the latest data, VSA will work with any local RAID, but support will apply only to RAID-10. Once you have completed the installation and configuration you can no longer add disks or resize your NFS datastore.
The installation procedure is very simple. First you install the VSA Manager, which later installs its plugin into the vSphere Client. When you connect to your vCenter, you simply run the VSA Wizard, which will help you determine the list of ESXi hosts that meet the VSA requirements. After that, a VSA virtual machine will be installed on each of the selected hosts, and then the wizard will help you easily and quickly raise vMotion between VSA nodes, enable HA and DRS.
On each of the VSA nodes, two disk volumes will be created: the first will be used under the NFS datastore, and the second will be used to store the NFS Datastore replica from one neighboring node. In principle, the first picture shows it well. Those VSA virtual machines that have been installed on the VSA cluster nodes will perform the following functions:
- NFS storage presentation to all your ESXi hosts
- Synchronize all replicas of NFS repositories
- Transfer of one of the NFS datastore replicas to online mode in case of a host crash, on which the main copy of this NFS storage was located.
Once you have completed the installation, you get a fully resilient and accessible storage system without a single point of failure.
Using VSA you are protected at once on several levels:
- Failure of a local disk does not affect the operation of your ESXi host and virtual machines at all.
- The failure of the ESXi host has absolutely no effect on the virtual machines located on its NFS Datastore. Another VSA cluster node instantly connects the replica of the failing NFS datastore with its ip address. Virtual machines from a fallen host will be automatically restarted using HA.
- You can go even further and enable Fault Tolerance for especially critical virtual machines. In this case, the failure of one ESXi host will be completely transparent to the virtual machines and their users.
VMware officially announces 99.9% availability of your virtual machines with properly configured VSA and HA.
I, alas, could not find deeper technical details, and the demo version of vSphere 5 is still available only to the select. Therefore, I switched to the financial side and tried to calculate the approximate cost of such a solution for a small or remote office. I relied on the prices that I gave me to Google and that are adequate to my region (Italy). Therefore, they can be very different from your prices, possible discounts and from your ideas what should be vSphere in a small office.
In my ideal remote office, I would have 3 HP Proliant DL380 G7 servers, in each of which I would place 6x600GB 10K disks. In its pure form, it would give me 10.8 TB. Considering all the RAIDs of usable space, we will have 2.7 TB, in three NFS storages of 900 GB each. Yes, as it seems to me that this is a big loss of disk space. And that's why I immediately thought about local RAID-5.
But on the other hand, let's all start from the price of one gigabyte for a completely redundant shared storage.
It was here that I found that the disks I needed would cost 368 euros, which would result in 6,624 euros for 18 disks. The announced price is VSA $ 5595, I think in Europe there will be the same figure, but in euros. Total we have 6624 + 5995 = 12,619 euros. We divide this figure by 2700 GB and get 4.67 euros per one gigabyte . I find it difficult to estimate expensive or cheap, so I would be very grateful if you could leave in the comments the names of competing VSA products and their cost per GB in your companies.
I assume that there are products that are cheaper, but there are also generally free ones, like Openfiler or FreeNAS. However, I would like to give some quite serious arguments in favor of VSA:
- Very easy installation process and therefore lower risk of error. The whole process takes place in a familiar interface and the wizard will make sure that everything is selected correctly and all steps are completed in the correct order. I personally had experience only with Openfiler and I can say that I did not immediately get used to its interface, which is why I had to redo everything twice.
- Integration with vCenter - all monitoring and control is concentrated in one place. And for sure there are already pre-configured alarms for VSA.
- Customer support for one vendor - I already had a couple of cases where the problem could be caused by both HP Virtual Connect and vSphere. Each time I had to contact both support services and each time I had to prove to them that this was their problem. By default, support services tried to simply shift all the blame from themselves to others. I am sure you also encountered similar problems. In the case of VSA, everything is much simpler - you will always have one person in charge. And when we suddenly had iSCSI storage running on Openfiler, I basically didn’t know what to do at all, because all my experience with it was limited to its configuration, and in Linux I had zero point tenths. So, the support service from one vendor is quite a serious advantage.
- If you decide to use a Windows server as iSCSI storage, or the same Openfiler, you will have to take care of fault tolerance at the host level - that is, provide synchronous replication, automatic switching. Everything is possible in principle, but again it takes more time, knowledge and support. In the case of VSA, this is all already included.
- You get all the benefits of NFS - automatic thin provisioning, easier access to virtual machine files for backup.
- In the third quarter of 2011, VMware will present a time-limited purchase offer for VMware vSphere 5 Essentials Plus and the vSphere Storage Appliance for $ 7.995, which gives us about 40% savings in the cost of the VMware vSphere Storage Appliance.
The only disadvantage of VSA at the moment is the high loss of disk space for protecting virtual machines, but as I said earlier, you need to focus on the cost of a gigabyte, which essentially should include not only the net cost of the disks and the redundancy provided, as well as operating expenses, which may consist of elapsed time, backup systems, support costs, etc.
As usual, any comments with valid criticism, additions, corrections of inaccuracies are welcome.
Source: https://habr.com/ru/post/124318/
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