Zstd instead of zlib?

Forza

In file /etc/xensource/xapi-ssl.conf there is a line compression=zlib. I read somewhere that XOA supports Zstd for backups. Is it possible to change this line to zstd to get improved performance?

; Autogenerated by /opt/xensource/libexec/xapissl 
; during xapi start-up.
;
fips = no
pid = /var/run/xapissl.pid
socket = r:TCP_NODELAY=1
socket = a:TCP_NODELAY=1
socket = l:TCP_NODELAY=1
socket = r:SO_KEEPALIVE=1
socket = a:SO_KEEPALIVE=1
compression = zlib


[xapi]
accept = :::443
connect = 80
cert = /etc/xensource/xapi-ssl.pem
ciphers = !SSLv2:RSA+AES128-SHA256:RSA+AES256-SHA:RSA+AES128-SHA:RSA+RC4-SHA:RSA+RC4-MD5:RSA+DES-CBC3-SHA
TIMEOUTclose = 0
options = NO_SSLv2
sslVersion = all

olivierlambert

I don't think it might be done "like that", plus I'm not sure the gain will be important.

Forza

I noticed that when transferring from a local SR the Domain Controller load goes up to about 300-400%. I am assuming this is partly because zlib isn't that effective CPU wise.

olivierlambert

Transferring what?

Forza

Normal backup jobs. In this case it is the "full" copy of the VDI I just moved to a local SR (due to maintenance on the NFS) I mentioned here https://xcp-ng.org/forum/topic/2247/moved-vdi-delta-backup-restarts-on-full. I see that Control Domain load is high and in top I see this:

At the moment it is only one disk left to transfer, but there were 3 to start with, so the load was higher in the beginning.