Storage Efficiency

Storage Efficiency – Compression 2

Storage Compression is one of those efficiency feature that isn’t talked about much. There are lots of ways in which you can implement compression like File System compression, storage array based compression, backup data compression etc. Storage Compression coupled with thin provisioning in CLARiiON/VNX Systems provide thin provisioned pools the much needed Space Reclamation capability that allows white space to be reclaimed. Remember one of the down side of implementing thin Provisioning for Server Virtualization environment was the thin space reclamation and Storage compression exactly brings that capability for the EMC CLARiiON/VNX arrays. Data written on LUNs are compressed based on meeting set thresholds/parameters. Generally runs as background task. When host reads compressed data, compressed data is decompressed in the Memory and made available to the host. A LUN when enabled for Compression becomes thin provisioned as well. Freed thin-LUN block space is made available for allocation at a storage pool level. Compression is best suited for data luns that contains whitespaces or recurring patterns. In EMC Arrays, when we enable compression on a LUN, Complete LUN processing is carried out after which data is processed in fixed 64KB increments encoding any recurring strings within data currently being processed and […]

Storage Efficiency – Storage Tiering 1

In a traditional Storage allocation model, Storage Requirement for most environments are typically satisfied by allocating the Storage based on the Capacity requirement rather than Performance because of either not knowing the Performance requirement of the application/environment during its initial deployment phase or due to lack of understanding of the importance of RAID and associated Disk penalties. Consider this, if there is a requirement to host 500 VMs of 18 IOPS each and 100 GB Capacity, We are looking at a Storage requirement of 6 TB (5 *100 GB + 25% Buffer Overhead) & 9000 IOPS. Considering a Read:Write ratio of 70:30 in RAID 5, we are looking at IOPS Requirement of 17100 which can be satisfied by 95 numbers of 15K drives. Consider RAID 5 configuration with 4+1 Drives for these 95 drives to satisfy the IOPS Requirement, We would be left with roughly 38 TB of Usable Space. But our capacity requirement was only 6 TB. How do we satisfy the IOPS and still right size for Capacity or how do we size for Capacity and still match the IOPS Requirement? Are we not spending additional $$$ to accommodate Performance requirements when most of the virtual workloads would […]

Storage Efficiency – Thin Provisioning 5

Traditionally, we allocate storage required for an environment upfront which is also referred as thick provisioning or fat provisioning. For Example, when there is a request for a 100 GB Virtual disk space, we go ahead with creation & allocation of 100 GB space. But have you analyzed how long would it take for that 100 GB Space to be consumed? If this is the case for a Single VM, Imagine the space that is being allocated to multiple virtual servers in the environment and how much space goes underutilized? In cases where they are optimally utilized, how long before they get consumed completely? Can we use the space for that time being for some other use cases or for provisioning more VMs? Another use case is optimizing the free space in datastore. Depending on environment there is a certain amount of buffer space that is reserved in every datastore. For Example, if we consider 20% as buffer space, in a 2 TB datastore we would be left with 400 GB free space per datastore. If you environment has 25 datastore of 2 TB each, you would be approximately leaving 10 TB (400 GB * 25) of unused space. Can we optimize this 10 TB space? Thin Provisioning help increase storage utilization […]