iSCSI question

[David Sheetz]

please bare with my lack of knowledge with iscsi but I need to know if a zvol I created for an iscsi target will overlap other volumes in any way.


Here is what I have, but the math does not add up, I fear if I format the vm-backups zvol it will overwrite data on other formats, can someone please

 

[Chris Moore]

I think there may be a terminology issue here, Try taking a look at this:
https://forums.freenas.org/index.php?resources/terminology-and-abbreviations-primer.37/
It looks like you have enabled thin provisioning.
Why do you say the math doesn't work out?

 

[David Sheetz]

If you look at the 2nd screenshot it shows more used than I have total. formatted we have about 10TiB total , the way volumes are grouped it confuses my calculations..... unless I look at used space and ignore any line that says pool I dont get 10.1 TiB

 

[Chris Moore]

If you look at the 2nd screenshot it shows more used than I have total. formatted we have about 10TiB total , the way volumes are grouped it confuses my calculations..... unless I look at used space and ignore any line that says pool I dont get 10.1 TiB

ZFS only uses the space as data is written to it. You don't format it like other file systems. If you have two datasets that occupy the same pool, both will have the same amount of space available to them but as data is written into one dataset, the space available to both datasets is reduced. In addition to which, there is compression. I have a zpool at work that has over 250 TB of data in it but the space on disk is only around 160 TB because it is highly compressible data.