Why do we need Azure backup for our VMs (disks) on azure, when azure storage account provides different replication options like LRS, ZRS, GRS, RA-GRS.
All the data is already replicate in different region (in case of GRS), what advantes I will get out of Azure Backup.
All the data is already replicate in different region (in case of
GRS), what advantes I will get out of Azure Backup.
Replication is not backup!
It is true that when you opt for GRS replication, 6 copies of your data is maintained (3 in primary and 3 in secondary) but when you delete the data from primary, data from secondary is automatically deleted.
UPDATE
You mean, if any data is deleted/corrupted due to some error/bug, can
be reproduced from backup and it is not possible in case of storage
replication.
You're absolutely correct!
But Microsoft sells "Azure backup and Site recovery" as a BCDR
strategy. In context of any disaster, why not just rely on Storage
replication. Any advantages of Azure backup/site recovery?
I have not used Azure backup so let me answer it from Storage Replication point of view. To put things simply, "In context of Azure, a disaster is not a disaster unless Microsoft thinks it is a disaster". Till the time that happens, you don't get access to secondary assuming you have opted for GRS replication (with RA-GRS, you obviously have an option to read the data from secondary at all times).
Furthermore if you choose LRS or Premium LRS replication and there's indeed a disaster in one data center, all of your data will be lost. With Azure Backup, you at least have a copy of your data lying somewhere safe and you could recreate your environment based on that backup.
I know this question is old but MS provide a solution for Disaster recovery by Storage account
We may have 2 solution for dealing with Disaster
https://learn.microsoft.com/en-us/azure/storage/common/storage-disaster-recovery-guidance?toc=/azure/storage/blobs/toc.json
it said :
If the primary endpoint becomes unavailable for any reason, the client is no longer able to write to the storage account. The following image shows the scenario where the primary has become unavailable, but no recovery has happened yet:
enter image description here
The customer initiates the account failover to the secondary endpoint. The failover process updates the DNS entry provided by Azure Storage so that the secondary endpoint becomes the new primary endpoint for your storage account, as shown in the following image:
enter image description here
Related
Since our RA-GZRS enabled Azure storage can't write to the secondary region when primary is down, thought of having another standby Azure storage to do the writes continuously.
The question is once the main storage account comes back, how sync the updates back to the main from standby? Can we write runbook using AzCopy.exe? Any other better Azure service/solution to accomplish sync process using AzCopy.exe/other as a background service?
Assuming the outage isn't severe enough that Microsoft doesn't failover to the secondary region. You can initiate the failover yourself, and then you would be able to write to the secondary region. This is essentially a DNS change which makes the secondary endpoint become the primary endpoint. Once the primary region becomes available again, you can change the storage account to geo-redundant storage, and then if required, repeat the failover.
See Initiate storage account failover and Storage account failover for more details.
I've searched the web and contacted technical support yet no one seems to be able to give me a straight answer on whether items in Azure Blob Storage are backed up or not.
What I mean is, do I need to create a twin storage account as a "backup" and program copies of all content from one storage to another, or are the contents of a client's Blob Storage automatically redundantly backed up by Microsoft?
I know with AWS, storage is redundantly backed up via onsite drives as well as across other nodes in the cluster.
do I need to create a twin storage account as a "backup" and program
copies of all content from one storage to another, or are the contents
of a client's Blob Storage automatically redundantly backed up by
Microsoft?
Yes, you will need to do backup manually. Azure Storage does not back up the contents of your storage account automatically.
Azure Storage does provide geo-redundant replication (provided you configure the redundancy level for your storage account as GRS or RA-GRS) but that is not back up. Once you delete content from your primary account (location, it will automatically be removed from secondary account (geo-redundant location).
Both AWS (EBS) and Azure(Blob Storage) options provides durability by replicating the data across different data centers. This is for the high availability and durability of the data to provide the guarantee by the cloud provider.
In order to ensure that your data is durable, Azure Storage has the
ability to keep (and manage) multiple copies of your data. This is
called replication, or sometimes redundancy. When you set up your
storage account, you select a replication type. In most cases, this
setting can be modified after the storage account is set up.
For more details refer the replication section in documentation.
If you need to capture changes to the storage and allow restore to previous versions (e.g In situations like data corruption or application feature requirements like restore points, backups), you need to take a SnapShot manually. This is common for both AWS and Azure.
For more details on creating a Snapshot of Blob in Azure refer the documentation.
We have written an application which writes media to and reads media from Azure Blob Storage.
I feel this may be a stupid question but is Azure Blob storage backed up?
Just wondering whether it is necessary to set this up explicitly?
Simple answer to your question is No. Azure Storage does not create back up of your data. This is something you would need to do.
#Pradeep mentions about data replication which is true but please do not confuse data replication with backup. Data replication is NOT data backup.
While it is true that a minimum of 3 copies of your blobs are maintained however if you delete the blob, all 3 copies are removed immediately.
Note: The data in your Microsoft Azure storage account is always replicated to ensure durability and high availability.
Replication copies your data, either within the same data center, or to a second data center, depending on which replication option you choose. Replication protects your data and preserves your application up-time in the event of transient hardware failures. If your data is replicated to a second data center, it's protected from a catastrophic failure in the primary location.
When you create a storage account, you can select one of the following replication options:
Locally redundant storage (LRS)
Zone-redundant storage (ZRS)
Geo-redundant storage (GRS)
Read-access geo-redundant storage (RA-GRS)
For more details, refer “Azure Storage replication”.
I have recently brought Microsoft Azure product for storage purpose of a NAS.
At first i chose the "read access geo redundant" and made a schedule for my NAS to backup.
Today i have changed it to local redundant (i saw the price difference) but my synology NAS is not finished backing up yet. Will it automaticly change to local redundant, or should i cancel the backup and re-do it?
To answer your question, you don't have to do anything. Azure will automatically convert your storage account's redundancy type from RAGRS to LRS.
To elaborate more, essentially the way RAGRS works is that data is written to the primary storage account and then through some background process the data is replicated to the secondary storage account. Once you change the redundancy to LRS, the replication stops.
One more point I would like to mention. If you're storing your data in blob storage for backup purpose only, may I suggest that you look at Cool Storage offering from Azure Storage. Compared to standard storage accounts, cost of storing data in a Cool Storage account is much lesser.
I know Azure will geo-replication a copy of current storage account to another location,
my questions is: can I access another location in program, even just read only
I asked this, because this allow me to build another deploy in different geo-location for performance and disaster-proof like what Azure did. For current setup, if I use same source of storage in different geo-location, I have to pay extra bandwidth cost.
You can only access your storage account by its primary name. In the event of failover, that name will be mapped to the alternate datacenter. You cannot access the failover storage directly, nor can you choose when to trigger a failover. For a multi-site setup as you described, you'd need to duplicate your data (which would then add the cost of storage in datacenter #2). This does give you ultimate flexibility in your DR and performance planning, but at an added cost of storage and bandwidth (egress-only).
Last week the storage team announced read-only access to the failover storage: Windows Azure Storage Redundancy Options and Read Access Geo Redundant Storage.
This means you can now deploy your application in a different datacenter which can be used for "full" failover (meaning that the storage will also be available there). Even if it's only read-only, your application will still be online - but simply in "degraded" mode.
The steps on how you can implement this with traffic manager are described here: http://fabriccontroller.net/blog/posts/adding-failover-to-your-application-with-read-access-geo-redundant-storage-and-the-windows-azure-traffic-manager/