VMware Solutions Discussions
VMware Solutions Discussions
So I still trying to understand how netapp disk space is allocated ....
I created a volume in an aggregate
vol create myvol myaggr 100g
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then create a lun for 50gb
lun create -s 50g -t vmware /vol/myvol/mylun
total used available
/vol/myvol/ 80GB 50GB 29GB 63% /vol/myvol/
/vol/myvol/.snapshot 20GB 0GB 19GB 0% /vol/myvol/.snapshot
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Then mounted the lun and moved a vm ~30gb vm to this lun
afterwards
I got this message
: monitor.globalStatus.nonCritical:warning]: /vol/myvol is full (using or reserving 98% of space and 0% of inodes, using 63% of reserve).
df -V -g shows
/vol/myvol/ 80GB 80GB 0GB 100% /vol/myvol/
/vol/myvol/.snapshot 20GB 0GB 19GB 0% /vol/myvol/.snapshot
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and in esx the actual size of the lun is using
vmfs3 49.8G 32.7G 17.1G 66% /vmfs/volumes/4e7a733c-8cf0ad8a-b1fe-001b2122b15d
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so I started with a 50gb lun in a 80gb volume. then i wrote 32.7gb into the 50gb lun.
what i still dont understand is why
df -V -g shows
/vol/myvol is 80gb full now and 0gb available now
why not 17.1 gb available instead?
Do you have any snapshots on this volume? "snap list myvol"?
Do you happen to know how VMware initializes datastore? I.e. - would it touch every block in a LUN during format?
snap list myvol
Volume myvol
working...
%/used %/total date name
---------- ---------- ------------ --------
1% ( 1%) 0% ( 0%) Sep 22 16:00 hourly.0
1% ( 1%) 0% ( 0%) Sep 22 12:00 hourly.1
2% ( 0%) 0% ( 0%) Sep 22 08:00 hourly.2
2% ( 1%) 1% ( 0%) Sep 22 00:00 nightly.0
3% ( 1%) 1% ( 0%) Sep 21 20:00 hourly.3
3% ( 0%) 1% ( 0%) Sep 21 16:11 hourly.4
And what does "df -rh myvol" show?
df -rh myvol
Filesystem total used avail reserved Mounted on
/vol/myvol/ 80GB 80GB 0GB 30GB /vol/myvol/
/vol/myvol/.snapshot 20GB 963MB 19GB 0MB /vol/myvol/.snapshot
why is used 80GB?
lun is 50GB
why is reserved 30GB?
By default when snapshot is created on volume with LUN Data ONTAP reserves amount of space that is “frozen” in snapshot on volume to ensure LUN still has space to write into it. Please read TR-3483 which explains all this in great details.
In general
- Snap reserve is meaningless on volumes containing LUN and simply reduce useable space
- Automatic (filer initiated) snapshots of volumes with LUNs will often result in inconsistent data on LUNs; the effect varies from hard to recover up to impossible to recover data from snapshot. Usually snapshots are initiated from host in coordination with applications on LUNs. You have automatic snapshots turned on.
i copied a vm to this volume. then removed it
from the esx host, the lun is showing as empty
but on the filer
df -V -g myvol
Filesystem total used avail capacity Mounted on
/vol/myvol/ 80GB 61GB 18GB 76% /vol/myvol/
/vol/myvol/.snapshot 20GB 30GB 0GB 154% /vol/myvol/.snapshot
lun show -v /vol/myvol/foo
/vol/myvol/foo 50g (53687091200) (r/w, online, mapped)
Serial#: dfkpVZfRtWuT
Share: none
Space Reservation: enabled (not honored by containing Aggregate)
Multiprotocol Type: vmware
Maps: test=200
Occupied Size: 30.3g (32552378368)
Creation Time: Sun Sep 25 18:50:24 PDT 2011
Cluster Shared Volume Information: 0x0
why is showing 61gb used and occupied size 30.3gb?