<div dir="ltr">Thank you Eugen,<div><br></div><div>I am noticing similar thing what you noticed. That means cinder lying to use or doesn't know how to calculate size of copy-on-write. </div><div><br></div><div>One more question, I have created 1G file using dd command and took incremental backup and found ceph only showing 28 MiB size of backup. Does that sound right? </div><div><br></div><div><br></div><div><span style="color:rgb(0,0,0);font-family:"Bitstream Vera Sans Mono",monospace;font-size:13px;white-space:pre;background-color:rgb(240,240,240)">root@ceph1:~# rbd -p backups du
NAME PROVISIONED USED
volume-285a49a6-0e03-49e5-abf1-1c1efbfeb5f2.backup.4351d9d3-85fa-4cd5-b21d-619b3385aefc@backup.4351d9d3-85fa-4cd5-b21d-619b3385aefc.snap.1684260707.1682937 10 GiB 68 MiB
volume-285a49a6-0e03-49e5-abf1-1c1efbfeb5f2.backup.4351d9d3-85fa-4cd5-b21d-619b3385aefc@backup.294b58af-771b-4a9f-bb7b-c37a4f84d678.snap.1684260787.943873 10 GiB 36 MiB
volume-285a49a6-0e03-49e5-abf1-1c1efbfeb5f2.backup.4351d9d3-85fa-4cd5-b21d-619b3385aefc@backup.c9652662-36bd-4e74-b822-f7ae10eb7246.snap.1684330702.6955926 10 GiB 28 MiB
volume-285a49a6-0e03-49e5-abf1-1c1efbfeb5f2.backup.4351d9d3-85fa-4cd5-b21d-619b3385aefc 10 GiB 0 B
</span></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, May 17, 2023 at 9:26 AM Eugen Block <<a href="mailto:eblock@nde.ag">eblock@nde.ag</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hi,<br>
<br>
just to visualize Rajat's response, ceph creates copy-on-write <br>
snapshots so the incremental backup doesn't really use much space. On <br>
a Victoria cloud I created one full backup of an almost empty volume <br>
(made an ext4 filesystem and mounted it, create one tiny file), then <br>
created a second tiny file and then made another incremental backup, <br>
this is what ceph sees:<br>
<br>
ceph01:~ # rbd du <backup_pool>/volume-6662f50a-a74c-47a4-8abd-a49069f3614c<br>
NAME <br>
PROVISIONED USED<br>
volume-6662f50a-a74c-47a4-8abd-a49069f3614c@backup.650a4f8f-7b61-447e-9eb9-767c74b15342.snap.1684329174.8419683 5 GiB 192 <br>
MiB<br>
volume-6662f50a-a74c-47a4-8abd-a49069f3614c@backup.1d358548-5d1d-4e03-9728-bb863c717910.snap.1684329450.9599462 5 GiB 16 <br>
MiB<br>
volume-6662f50a-a74c-47a4-8abd-a49069f3614c <br>
5 GiB 0 B<br>
<TOTAL><br>
<br>
backup.650a4f8f-7b61-447e-9eb9-767c74b15342 (using 192 MiB) is the <br>
full backup, backup.1d358548-5d1d-4e03-9728-bb863c717910 is the <br>
incremental backup (using 16 MiB).<br>
<br>
Zitat von Rajat Dhasmana <<a href="mailto:rdhasman@redhat.com" target="_blank">rdhasman@redhat.com</a>>:<br>
<br>
> Hi Satish,<br>
><br>
> Did you check the size of the actual backup file in ceph storage? It should<br>
> be created in the *backups* pool[1].<br>
> Cinder shows the same size of incremental backup as a normal backup but<br>
> file size should be different from<br>
> the size shown in cinder DB records. Also file size of incremental backup<br>
> should not be the same as the file size of full backup.<br>
><br>
> [1]<br>
> <a href="https://github.com/openstack/devstack/blob/34afa91fc9f830fc8e1fdc4d76e7aa6d4248eaaa/lib/cinder_backups/ceph#L22" rel="noreferrer" target="_blank">https://github.com/openstack/devstack/blob/34afa91fc9f830fc8e1fdc4d76e7aa6d4248eaaa/lib/cinder_backups/ceph#L22</a><br>
><br>
> Thanks<br>
> Rajat Dhasmana<br>
><br>
> On Wed, May 17, 2023 at 12:25 AM Satish Patel <<a href="mailto:satish.txt@gmail.com" target="_blank">satish.txt@gmail.com</a>> wrote:<br>
><br>
>> Folks,<br>
>><br>
>> I have ceph storage for my openstack and configure cinder-volume and<br>
>> cinder-backup service for my disaster solution. I am trying to use the<br>
>> cinder-backup incremental option to save storage space but somehow It<br>
>> doesn't work the way it should work.<br>
>><br>
>> Whenever I take incremental backup it shows a similar size of original<br>
>> volume. Technically It should be smaller. Question is does ceph<br>
>> support incremental backup with cinder?<br>
>><br>
>> I am running a Yoga release.<br>
>><br>
>> $ openstack volume list<br>
>> +--------------------------------------+------------+------------+------+-------------------------------------+<br>
>> | ID | Name | Status | <br>
>> Size | Attached to |<br>
>> +--------------------------------------+------------+------------+------+-------------------------------------+<br>
>> | 285a49a6-0e03-49e5-abf1-1c1efbfeb5f2 | spatel-vol | backing-up | <br>
>> 10 | Attached to spatel-foo on /dev/sdc |<br>
>> +--------------------------------------+------------+------------+------+-------------------------------------+<br>
>><br>
>> ### Create full backup<br>
>> $ openstack volume backup create --name spatel-vol-backup spatel-vol --force<br>
>> +-------+--------------------------------------+<br>
>> | Field | Value |<br>
>> +-------+--------------------------------------+<br>
>> | id | 4351d9d3-85fa-4cd5-b21d-619b3385aefc |<br>
>> | name | spatel-vol-backup |<br>
>> +-------+--------------------------------------+<br>
>><br>
>> ### Create incremental<br>
>> $ openstack volume backup create --name spatel-vol-backup-1 <br>
>> --incremental --force spatel-vol<br>
>> +-------+--------------------------------------+<br>
>> | Field | Value |<br>
>> +-------+--------------------------------------+<br>
>> | id | 294b58af-771b-4a9f-bb7b-c37a4f84d678 |<br>
>> | name | spatel-vol-backup-1 |<br>
>> +-------+--------------------------------------+<br>
>><br>
>> $ openstack volume backup list<br>
>> +--------------------------------------+---------------------+-------------+-----------+------+<br>
>> | ID | Name | <br>
>> Description | Status | Size |<br>
>> +--------------------------------------+---------------------+-------------+-----------+------+<br>
>> | 294b58af-771b-4a9f-bb7b-c37a4f84d678 | spatel-vol-backup-1 | None <br>
>> | available | 10 |<br>
>> | 4351d9d3-85fa-4cd5-b21d-619b3385aefc | spatel-vol-backup | None <br>
>> | available | 10 |<br>
>> +--------------------------------------+---------------------+-------------+-----------+------+<br>
>><br>
>><br>
>> My incremental backup still shows 10G size which should be lower <br>
>> compared to the first backup.<br>
>><br>
>><br>
>><br>
<br>
<br>
<br>
<br>
</blockquote></div>