Okay, more clear report:
$ lsblk -do NAME,ROTA,DISC-GRAN
El 10/4/19 a les 14:12, Pascal ha escrit:
> I would tend to say that "discard" is not related to "ssd" while "rotational"
> is...
>
> Le mer. 10 avr. 2019 à 14:06, Pascal a écrit :
>
>> lsblk -ndo ROTA /dev/sda
>>
>> sorry for the bad
I would tend to say that "discard" is not related to "ssd" while "rotational"
is...
Le mer. 10 avr. 2019 à 14:06, Pascal a écrit :
> lsblk -ndo ROTA /dev/sda
>
> sorry for the bad copy.
>
> Le mer. 10 avr. 2019 à 12:52, Narcis Garcia a
> écrit :
>
>> Can be this rotational detection be
lsblk -ndo ROTA /dev/sda
sorry for the bad copy.
Le mer. 10 avr. 2019 à 12:52, Narcis Garcia a
écrit :
> Can be this rotational detection be affecting in this case?
>
> https://lists.openvz.org/pipermail/users/2019-April/007564.html
> (Devuan 1.0 VM with distro kernel succeeds with lsblk and
Can be this rotational detection be affecting in this case?
https://lists.openvz.org/pipermail/users/2019-April/007564.html
(Devuan 1.0 VM with distro kernel succeeds with lsblk and fstrim)
How can I make guest OS to detect device as no rotational or true SSD?
El 10/4/19 a les 12:47, Narcis
Pascal, I don't understand syntax you use for lsblk.
I see this with:
$ cat /sys/block/sda/queue/rotational
El 10/4/19 a les 12:38, Pascal ha escrit:
> it's ok with discard=unmap option (even if the disc is thick-provisioned)
> : the block used by the test file appears (VM side) or is reset
it's ok with discard=unmap option (even if the disc is thick-provisioned)
: the block used by the test file appears (VM side) or is reset (host
side) at zero.
notice that lsblk "thinks" that the disc is a rotational disk (eg. not
really SSD) :
lsblk -ndo /dev/sda
1
thanks for explanations
I see now the simple:
-device virtio-scsi-pci
makes all -disk (media=disk) to be detected by guest as SSD
Additionally, adding "discard=unmap,detect-zeroes=unmap" to disk image
specification makes host Qemu to discard sparse image holes and recover
host disk space when guest sends discard signal!
A test to check if guest Linux kernel treats vdisk as SSD:
Instead of:
mount /dev/sda1 /ssd
mount
Do this:
mount -o discard /dev/sda1 /ssd
mount
Anyway I don't think 'strings' test must be reflecting real blocks
discard behavior if not:
1. qemu taking image file actions for guest discard signals
1. You need to set the discard option for the -drive parameter, eg
-drive if=none,...,format=raw,discard=unmap since the default is still
to simply ignore discards.
You may also want to set the detect-zeroes option to unmap, to discard
all-zero blocks instead of actually writing them.
2.
Thank you.
* I use RAW images because of it's easier to offline mount/chroot when
some issue happens.
* I call directly qemu instead of libvirt
I'll try to parse these parameters to a qemu-system call.
El 8/4/19 a les 22:03, Friedrich Oslage ha escrit:
> Yes.
>
> You'll have to use the
Yes.
You'll have to use the virtio-scsi driver, to my knowledge it's the only
driver that supports block discards.
Quick example:
# create a new empty disk
$ qemu-img create -f qcow2 disk.qcow2 10G
# check size, should only be a few kilobytes
$ du -sh disk.qcow2
# add it to your vm
$
No; I want to study the possibility of recovering allocated blocs of
host filesystem when guest filesystem removes its files (unallocates its
blocks).
Host -> HD or SSD (independent) with sparse-mode image
Guest -> Virtual SSD (to signal discards)
El 5/4/19 a les 16:01, Pascal ha escrit:
>
Is there a way to specify a disk to be detected as an SSD drive?
Once reached this, I want to look for the possibility to recover host
space when a guest discards disk image blocks, and this image is RAW
format and sparse allocated file.
Thank you.
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