Open-E JovianDSS ver.1.0 up00 Release Notes
Release date: 08.07.2014
Build: 12491
Please note that ver.1.0 up00 is the first release of Open-E JovianDSS. For more information about the software please visit http://www.open-e.com/products/jovian-data-storage-software/
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Known issues
Browser recommendation
It is strongly recommend to use Mozilla Firefox browser to navigate the system’s GUI. When using other browser some slight problems with the display of the content may occur.
System as a guest in virtual environments
Hyper-V:
System doesn't work correctly as a Hyper-V virtual machine (guest). There is a problem with hv_netvsc network driver.
VMware ESXi:
In case of installing the system as a VMware ESXi guest please use following settings:
- Guest OS: Other 2.6.x Linux ( 64bit )
- Number of Cores: 4
- Memory: Minimum 8GB
- Network Adapter: VMXNET 3
- SCSI Controller Type: Paravirtual or LSI Logic SAS
- Boot Disk : 20GB Thick Provision
- Add at least 6 virtual disk
- Edit Settings->Options->Advanced-General->Configuration-> Add row: disk.EnableUUID : TRUE
Reclaim of deleted blocks on thin-provisioned LUNs in various systems
In case of deleting a large amount of data, reclaim deleted blocks on thin-provisioned LUNs in Windows 2012 can significantly slow down system performance. In case of predicting the frequent deletions large amounts of data, we recommend to turning off automatic reclaim function in Windows 2012. It can be done by disabling the "file-delete notification" feature in the system registry. To do this, please follow these steps:
- start Registry Editor
- locate the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem
- double-click DisableDeleteNotification.
- in the Value data box, enter a value of 1, and then click OK.
In order to reclaim the free space on Windows 2012 please change the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem\DisableDeleteNotification key value back to 0 and use "Optimize" tool located in Disc Management->[disk]->Properties->Tools. As the operation can generate very high load in the system it is recommended to do this after working hours.
In case of VMware ESXi the automatic reclaim feature is disabled by default. To reclaim the space of deleted blocks on thin-provisioned LUNs please use vmkfstools. For details please refer the VMware Knowledge Base:
For VMware ESXi 5.0: http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2014849
For VMware ESXi 5.5 and newer: https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2057513
In case of using Windows 2008 or Citrix Server there is no possibility to reclaim the space released by deleted data of thin-provisioned LUNs.
Deduplication issues and recommendations
Please be aware that deleting the zvol with deduplication functionality can generate very high load in the system and lead to unstable behavior. It is strongly recommended to perform this operation only after working hours. To avoid this issue please use (if possible) single zvol on zpools dedicated for deduplication and delete the zpool which include the single zvol.
To determine how much System RAM you need for deduplication, use this formula:
(Size of Zvol / Volume block size) * 320B / 0.5 / 0.25
Where:
320B - size of entry in DDT table
0.5 - Percentage RAM reservation for ARC (50%)
0.25 - Percentage DDT reservation in ARC (25%)
Example for 1TB data and 64KB Volume block size:
(1099511627776B / 65536B) * 320B / 0.5 / 0.25 = 42949672960B
42949672960B / 1024 / 1024 / 1024 = 40GB
so for every extra 1TB of storage, system needs extra 40GB RAM
IMPORTANT: The above calculations only apply to the worst case scenario, when data is completely unique and will not be deduplicated. For the deduplicable data, the need for RAM drastically decreases.
Zvols configuration issues and recommendations
It is strongly recommended to match the client file-system block size to zvol volume block size. For example, when using default 64k zvol volume block size, the Windows Allocation unit size of NTFS need to be set to 64k.
Target number limit
More than 20 targets in the system can cause the Web Browser to ask about terminating JavaScript, please answer "wait".
In case of more than 60 targets, GUI will not be displayed correctly.
This issue will be fixed in next releases.
Targets with the same name are not assigned correctly
Having two or more targets with the same name but belonging to various Zpool, will cause that all targets with the same name will be assigned to one Zpool during the import process.
Performance tuning
Sync always for Zvol is the safest option and is set by default. However, it can cause write performance decreases since all operations are written and flushed to storage.
Sync standard option causes write performance to be better, but some (cached) data can be lost in case of a sudden power failure. So please use this option only in environments equipped with UPS.
Installation on disks containing LVM metadata
There is no possibility to install the system on disks containing LVM metadata. You can clear such disks before installation use the “Remove ZFS data structures and disks partitions” function located in Extended tools in the running version.
Import Zpool with broken write log
There is no option to import Zpool with a broken write log disk using system’s functions.This is why it is STONGLY recommended to use mirrored disks for write logs. In case it is necessary to import Zpool with broken write log disk, please contact Support.
Replacing disks in data groups with larger ones can make you exceed storage license capacity
In case of replacing damaged disks with larger ones, the size of the entire Zpool can be increased, so please make sure that the new size will not exceed your purchased storage license.
Periodically after some operations, GUI needs to be manually refreshed
After performing some operations, such as resilvering, GUI shows outdated information. In this case please refresh the web page manually by pressing F5 on your keyboard. This issue will be fixed in next releases.
Replacing a disk in data group for a smaller one causes an error and makes the disk disappear from the list of available disks
Operation of replacing a disk in data group for a smaller one causes an error "zpool unknown error, exit code 255" and the disk becomes unavailable to use. In order to re-use this disk, please use function "Remove ZFS data structures and disks partitions" under console.
It is impossible to change the transport service for Mellanox's InfiniBand in real-time
Changing between connected and datagram mode for Mellanox's InfiniBand under console finished successfully, but this change will be applied after reboot.
It is strongly recommended to use 64KB or higher Volume block size
Block sizes smaller than 64KB cause very high memory consumption in case of using deduplication or Read Cache.
RAM recommendations for Read Cache
To determine how much System RAM you need with Read Cache, use this formula:
RAM needed = (Size of Read Cache - reserved size and labels) * bytes reserved by l2hdr structure / Volume block size
For 8KB Volume block size and 1TB Read Cache:
RAM needed = (1099511627776B - 4718592B) * 432B / 8192B = 57981809664B
57981809664B / 1024 / 1024 / 1024 = 54GB
Where:
1099511627776B - 1TB Read Cache
4718592B - reserved size and labels
432B - bytes reserved by l2hdr structure
8192B - Volume block size
For 64KB Volume block size and 1TB Read Cache:
RAM needed = (1099511627776B - 4718592B) * 432B / 65536B = 7247726208B
7247726208B / 1024 / 1024 /1024 = 6.75GB
Sometimes after multiple operations of adding and detaching disks, detaching from a group may fail but the disk will be shown on a list of available disks
Multiple operations of addding and detaching disks from groups can cause that the next operation of detaching will fail, but the disk will be shown on a list of available disks. When trying to add this disk to one group it will fail with the following error "[zfslib-wrap-zpool-ZpoolCmdError-1] invalid vdev specification". In this case please detach this disk once again.
After removing disks from groups they are not displayed on a list of available disks
Sometimes after removing disks from groups, Spare/Read Cache/Write Log disks are displayed on a list of unassigned disks, but they are not on a list of available disks. In this case, please use the refresh button located in adding group form.
More than three interconnected JBODs can cause that during system boot you will see messages from udev and disks from fourth and above JBODs will be not displayed
More than three interconnected JBODs can cause that during boot you will see messages similar to:
“udev_db_add_device: unable to create db file '/dev/.udev/db/\x2fdevices\x2fpci0000:00\x2f0000:00:04.0\x2f0000:17:00.0\x2f0000:18:0a.0\x2f0000:1f:00.0\x2fhost11\x2fport-11:0\x2fexpander-11:0\x2fport-11:0:0\x2fexpander-11:1\x2fport-11:1:0\x2fexpander-11:2\x2fport-11:2:17\x2fexpander-11:3\x2fport-11:3:1\x2fend_device-11:3:1\x2fbsg\x2fend_device-11:3:1': File name too long”,
and disks will not be displayed at GUI. This issue will be fixed in next releases.
Reusing disks from an exported and deleted Zpool
After deleting an exported Zpool, not all disks included in the exported Zpool are immediately available to reuse. Before they become available to reuse, disks which were used as Spare and Read Cache must be additionally cleaned by “Remove ZFS data structures and disks partitions” function located in “Extended tools”.
Disabling the Scrub scanner scheduler
There is no option to disable Scrub scanner scheduler. As a workaround, please set a non-existing date (e.g. 31st of February) as a term of invoking Scrub scanner.