Zextras suite storage management system or Powerstore provides Zimbra users with four very useful volume operations which are only available through the CLI to avoid any volume management errors. These useful volume-related tools are BLOB coherency check, item deduplication, move items between volumes, and volume statistics.
BLOB Coherency Check
This volume operation performs a coherency check on volume BLOBs. You can run it on one or even several volumes at a time. This is a substitute for the deprecated
zmblobchk command. This operation can run a BLOB coherency check on both volumes and mailboxes.
How many times have you found an item that cannot be opened, viewed, or seemed corrupted? This happens quite often and, in most cases, is caused when Zimbra doesn’t find the corresponding BLOB for an item. Another cause could be the BLOB itself which can be corrupted due to various reasons.
You can easily run this feature using
doCheckBlobs. It first checks if the corresponding BLOB exists for every item, then checks if the corresponding items exist for every BLOB, then it uses the hash SHA function to check if the BLOB’s filename including its content corresponds to the file’s hash, and finally, checks if the BLOB size matches corresponding items.
In action, it would be something as simple as
zxsuite powerstore doCheckBlobs start
which starts a BLOB coherency check on all volumes.
You can take benefit from item deduplication to reduce the space used by duplicated items in a volume. It simply stores each item only once, and referencing it when needed in a different location leads to huge savings in terms of space.
Large enterprises with email-based correspondence that quickly grows to an incredible size benefit the most from this feature. The advantage becomes even more prominent in servers with a large number of items.
How It Works
The only thing you need to perform this operation is to specify the name of the target volume and the
zxsuite powerstore doDeduplicate command. For example, the following command starts deduplication on volume myVolume:
zxsuite powerstore doDeduplicate myVolume
Move Items Between Volumes
Sometimes you need to move the data from a volume to another, including index volumes. This volume operation allows system administrators to achieve this goal using only the name of the source and destination volumes.
This operation becomes pretty handy when a system administrator needs to suspend an old volume without losing the data. There can be various situations in which you need to stop using a volume, such as upgrading to new hardware, creating a volume in the wrong location, organizing, or centralizing volumes.
How It Works
As we said before, you only need the name of the source and destination volumes besides the
zxsuite powerstore doVolumeToVolumeMove command for this operation. For instance
zxsuite powerstore doVolumeToVolumeMove sourceName destinationName
To display some statistics about the specified volume such as path, size, compression threshold, number of BLOBs, etc.
How It Works
The only needed information is the volume ID and the command
zxsuite powerstore getVolumeStats. For instance,
zxsuite powerstore getVolumeStats volumeID
You can find a lot more about these features in Zextras Powerstore documentation.