Hello.
Recently i replaced SSD drives on hosts and faced a problem.
Veey slow performance in VMs.
Lot of time i couldn't understand what happens.
I used Crucial CX500, but bought Samsung 870 QVO (as in tests it is faster?)
So, after some time i found (in experimental way) that with "discard" option enabled - performance is very slow. (disk io 80-99%, disk response time in VM up to 4000ms)
Disabled, the things became better but not good (IO 40-80%, response time 200-1400ms)
So,i disabled "ssd" option. Better but...
After googling a lot i found that 870QVO doesn't support disard. Hmm..
I rebuild storages with that config:
vgcreate -s 4M
lvcreate --thinpool xyz -c 128K -Zn myvg
And only after that (the key was -Zn!) VMs on 870QVO, Ryzen5 SSD, Goodram CX400 works fine!
So, i thought that maybe it will be a good idea to disable zeroing and use 128K chunk size as default for lvm thin and lvm thick?)
Who needs more that 30Tib can recreate it by yourself...
But in fact such config will give the ability to use any SSDs
Recently i replaced SSD drives on hosts and faced a problem.
Veey slow performance in VMs.
Lot of time i couldn't understand what happens.
I used Crucial CX500, but bought Samsung 870 QVO (as in tests it is faster?)
So, after some time i found (in experimental way) that with "discard" option enabled - performance is very slow. (disk io 80-99%, disk response time in VM up to 4000ms)
Disabled, the things became better but not good (IO 40-80%, response time 200-1400ms)
So,i disabled "ssd" option. Better but...
After googling a lot i found that 870QVO doesn't support disard. Hmm..
I rebuild storages with that config:
vgcreate -s 4M
lvcreate --thinpool xyz -c 128K -Zn myvg
And only after that (the key was -Zn!) VMs on 870QVO, Ryzen5 SSD, Goodram CX400 works fine!
So, i thought that maybe it will be a good idea to disable zeroing and use 128K chunk size as default for lvm thin and lvm thick?)
Who needs more that 30Tib can recreate it by yourself...
But in fact such config will give the ability to use any SSDs
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