When you try to create shadow copies on large volumes that have a small cluster size (less than 4 kilobytes), or if you take snapshots of several very large volumes at the same time, the VSS software provider may use a larger paged pool memory allocation during the shadow copy creation than is required. If there is not sufficient paged pool memory available for the allocation, the shadow copy cannot complete and may cause the loss of all previous shadow copy tasks. Follow this article and apply the fix:
Fusion IO has achieved One Billion iops !!!
Very Cool integration:
I just recently stumbled upon a new Youtube user called EMCProvenSolutions Looks like guys from EMC Ireland have put together a couple really good video series mostly on VMware and some replication methodologies. Go check them out. I love the Irish narration.
When it comes to deduplicating your data, a smarter approach is to dedupe at the source. Why wait until all that data gets to storage to dedupe it? There is a better way. In this video see how we to find a better way to use Mini Coopers as an analogy for data storage. Symantec BackupExec and NetBackup with Dedupe Everywhere eliminate the need for expensive “dedupe” storage by performing dedupe as part of the backup process. Don’t traverse your network with large volumes of data before deduplication occurs. Dedupe Everywhere: on the client, on the media server, on appliances, and for virtual machines.
EMC recently launched their new VNX storage line which is a unified storage platform with one management framework supporting file, block, and object optimized for virtual applications. From that line they also produced a more affordable “VNXe” model for small business and remote offices. There are a number of ways to protect the VNXe including snapshots, replication and NDMP backups. Typically I would use a couple different combinations of these three technologies depending on the business need and data risk, but today I am only going to go into detail with backing up the VNXe using Backup Exec as it is the most popular choice for small and medium businesses which is fitting for the VNXe.
Error:
Unable to connect to the OpenStorage device. Ensure that the network is properly configured between the device and the media server.
Environment:
Backup Server: Symantec Backup Exec 2010 R3
OpenStorage Device: DataDomain DD670 running 5.0.0.7-226726
Today I was configuring DDBOOST for Backup Exec 2010 R3 using a replicated pair of DD670’s. The DD670’s were pre-configured with version 4.9 which I upgraded to 5.0.0.7-226726. I setup the 670 with a standard configuration and then configured a storageunit.
Event ID: 114113
Description:
Checkpoint validations (hfschecks) of server Checkpoints are performed to ensure that checkpoints are valid for disaster recovery needs. A regularly scheduled hfscheck did not take place as scheduled. If hfschecks are not being performed disaster recovery may not be possible.
Remedy:
Check to make sure that checkpoint is configured and enable it if it’s not. Check to make sure checkpoint validation is configured and enable it if it’s not. If checkpoint and validation are enabled and schedule and either no checkpoint was taken or no validation occurred, contact your support center.
How Backup Exec Deduplication Works:
Deduplication works by dividing data into 128K segments and then storing the segments in a deduplication storage folder, along with a database that tracks the segments. Data is not stored again when a backup encounters a segment that is already stored in the deduplication storage folder. So, if you back up the same unchanged file over and over again, it is stored only one time in the deduplication storage folder.
Where the Backup Exec Deduplication Option Works Best
Deduplication only happens when the Deduplication Option detects blocks of data that are in fact the same. Operating system files deduplicate well. They are the same across multiple systems and do not change often.
Deduplication works well in the following scenarios:
? With Windows and Linux file system data
? Where the same file is backed up multiple times
? Where the percentage of data that changes is small
Where Other Backup Exec Options Work Best
Deduplication does not work well if data changes frequently or if the Deduplication Option cannot detect the duplicated blocks of data. For example, when a new bit of data is inserted at the beginning of a large file (VMDKs), the blocks of data are shifted so that none of them will match. Therefore, the file is not deduplicated.
This segment shift works against the Deduplication Option in cases where a non-file system backup is sent to the deduplication storage folder. These backups appear as one very large stream to the deduplication storage folder. Because of this, adding data early in the data stream causes the rest of the data stream to deduplicate poorly, if at all (Example: Exchange Database maintenance).
The good news is that in these cases, some Backup Exec agents can avoid backing up duplicate data with the use of traditional differential and incremental backup techniques. For example, when backing up VMWare or Hyper-V virtual machines, significantly better deduplication rates will be achieved by ensuring the Backup Exec Agent for Windows Systems is installed in each of the virtual machines and backing those machines up as though they are physical machines. Doing so allows the deduplication option to read each of the files and folders within the virtual machine and deduplicate
those individual files. (NOTE: The Agent for VMWare Virtual Machines and the Agent for Microsoft Hyper-V licenses allow for unlimited usage of the Agent for Windows Systems within the same host machine.)
Expectations for the Deduplication Option
Deduplication is data-dependent. That is, the amount of deduplication that you are going to get out of a particular data set depends on what is in the data set. Data that is all unique is not going to benefit from deduplication. Data that contains many copies of the same data will benefit from deduplication.
If there is a terabyte of source data that doesn’t have any duplicate information in it, the deduplication storage folder is going to need a terabyte of space to store it.
A deduplication storage folder has significant memory and disk space requirements. Make sure to review the requirements for the Deduplication Option before implementing it. While the option may initially work on a system that does not meet these requirements, as time goes by and the deduplication storage folder fills up, a lack of memory and disk space will cause problems.
A deduplication storage folder is significantly more complex than a backup-to-disk folder. Detecting duplicate data, tracking it in a database, and managing the interconnected links in the deduplication folder all adds up to significant memory and CPU usage. Memory, processing, and time is traded for reduced storage space requirements. This trade-off needs to be considered when choosing to use a deduplication storage folder over a backup-to-disk folder.