iscsi available size
SeventhSon
2 Posts
November 25, 2017, 12:17 pmQuote from SeventhSon on November 25, 2017, 12:17 pmHi!
I've created 3 nodes in VirtualBox, added one 10GB HDD to each node.
iSCSI manager shows me 1GB-100TB available size, at the same moment I see about 15GB(and I think it is true, 10GB*3/2 replicas) at the main dashboard.
Why iSCSI disk manager does not show available disk space correctly?
I see this is a serious problem as I can not set ISCSI size manually, only 10-20-30 GB.
Hi!
I've created 3 nodes in VirtualBox, added one 10GB HDD to each node.
iSCSI manager shows me 1GB-100TB available size, at the same moment I see about 15GB(and I think it is true, 10GB*3/2 replicas) at the main dashboard.
Why iSCSI disk manager does not show available disk space correctly?
I see this is a serious problem as I can not set ISCSI size manually, only 10-20-30 GB.
Last edited on November 25, 2017, 12:21 pm by SeventhSon · #1
admin
2,930 Posts
November 25, 2017, 3:00 pmQuote from admin on November 25, 2017, 3:00 pmThere is a difference between physical disk capacity and iSCSI disk capacity. Ceph is a cloud technology which allows you to over commit / thin provision storage. Assume you have 10 TB of physical storage available, you are allowed to create several 100 TB iSCSI disks and they will work fine ( you can format them as 100 TB and the iSCSI initiator will see them as 100 TB each ). Now as your client starts to write and fill the disks by close to 10 TB, you will need to start adding more physical storage ( aka OSDs ). The dashboard will show you % fill usage of your physical disks so to warn if you are getting close to full..you can/should setup email notifications ad PetaSAN will send you email alarms if physical storage is starting to fill. Of course if you want to play safe you can have all the physical storage available from the start so you do not worry about it but i wanted to make the distinction between physical capacity and iSCSI capacity. The 100 TB max value for iSCSI disks set in the ui slider is fixed and not dependent on current available storage, it is the max value we see that could be used in real use cases.
Another thing, the min hard disk size we support is 32 GB. I believe 10 GB will not work since we need to create both OSD and journal.
The docs do explain both of the above points, so please have look at them they are straight forward.
There is a difference between physical disk capacity and iSCSI disk capacity. Ceph is a cloud technology which allows you to over commit / thin provision storage. Assume you have 10 TB of physical storage available, you are allowed to create several 100 TB iSCSI disks and they will work fine ( you can format them as 100 TB and the iSCSI initiator will see them as 100 TB each ). Now as your client starts to write and fill the disks by close to 10 TB, you will need to start adding more physical storage ( aka OSDs ). The dashboard will show you % fill usage of your physical disks so to warn if you are getting close to full..you can/should setup email notifications ad PetaSAN will send you email alarms if physical storage is starting to fill. Of course if you want to play safe you can have all the physical storage available from the start so you do not worry about it but i wanted to make the distinction between physical capacity and iSCSI capacity. The 100 TB max value for iSCSI disks set in the ui slider is fixed and not dependent on current available storage, it is the max value we see that could be used in real use cases.
Another thing, the min hard disk size we support is 32 GB. I believe 10 GB will not work since we need to create both OSD and journal.
The docs do explain both of the above points, so please have look at them they are straight forward.
Last edited on November 25, 2017, 3:00 pm by admin · #2
iscsi available size
SeventhSon
2 Posts
Quote from SeventhSon on November 25, 2017, 12:17 pmHi!
I've created 3 nodes in VirtualBox, added one 10GB HDD to each node.
iSCSI manager shows me 1GB-100TB available size, at the same moment I see about 15GB(and I think it is true, 10GB*3/2 replicas) at the main dashboard.
Why iSCSI disk manager does not show available disk space correctly?
I see this is a serious problem as I can not set ISCSI size manually, only 10-20-30 GB.
Hi!
I've created 3 nodes in VirtualBox, added one 10GB HDD to each node.
iSCSI manager shows me 1GB-100TB available size, at the same moment I see about 15GB(and I think it is true, 10GB*3/2 replicas) at the main dashboard.
Why iSCSI disk manager does not show available disk space correctly?
I see this is a serious problem as I can not set ISCSI size manually, only 10-20-30 GB.
admin
2,930 Posts
Quote from admin on November 25, 2017, 3:00 pmThere is a difference between physical disk capacity and iSCSI disk capacity. Ceph is a cloud technology which allows you to over commit / thin provision storage. Assume you have 10 TB of physical storage available, you are allowed to create several 100 TB iSCSI disks and they will work fine ( you can format them as 100 TB and the iSCSI initiator will see them as 100 TB each ). Now as your client starts to write and fill the disks by close to 10 TB, you will need to start adding more physical storage ( aka OSDs ). The dashboard will show you % fill usage of your physical disks so to warn if you are getting close to full..you can/should setup email notifications ad PetaSAN will send you email alarms if physical storage is starting to fill. Of course if you want to play safe you can have all the physical storage available from the start so you do not worry about it but i wanted to make the distinction between physical capacity and iSCSI capacity. The 100 TB max value for iSCSI disks set in the ui slider is fixed and not dependent on current available storage, it is the max value we see that could be used in real use cases.
Another thing, the min hard disk size we support is 32 GB. I believe 10 GB will not work since we need to create both OSD and journal.
The docs do explain both of the above points, so please have look at them they are straight forward.
There is a difference between physical disk capacity and iSCSI disk capacity. Ceph is a cloud technology which allows you to over commit / thin provision storage. Assume you have 10 TB of physical storage available, you are allowed to create several 100 TB iSCSI disks and they will work fine ( you can format them as 100 TB and the iSCSI initiator will see them as 100 TB each ). Now as your client starts to write and fill the disks by close to 10 TB, you will need to start adding more physical storage ( aka OSDs ). The dashboard will show you % fill usage of your physical disks so to warn if you are getting close to full..you can/should setup email notifications ad PetaSAN will send you email alarms if physical storage is starting to fill. Of course if you want to play safe you can have all the physical storage available from the start so you do not worry about it but i wanted to make the distinction between physical capacity and iSCSI capacity. The 100 TB max value for iSCSI disks set in the ui slider is fixed and not dependent on current available storage, it is the max value we see that could be used in real use cases.
Another thing, the min hard disk size we support is 32 GB. I believe 10 GB will not work since we need to create both OSD and journal.
The docs do explain both of the above points, so please have look at them they are straight forward.