Q: ext4 noatime/nidiratime for oVirt node mount points
Hi ! Is it safe to turn on these options (noatime, nodiratime) in oVirt node fstab for these mount points? /home / /tmp /var /var/log /var/log/audit Node 4.2 installed on CentOS, not with node DVD. Thanks.
What is the purpose in putting these directives in for the hypervisor? On Thu, Jan 4, 2018 at 6:46 AM, andreil1 <andreil1@starlett.lv> wrote:
Hi !
Is it safe to turn on these options (noatime, nodiratime) in oVirt node fstab for these mount points? /home / /tmp /var /var/log /var/log/audit
Node 4.2 installed on CentOS, not with node DVD.
Thanks.
_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
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On 4 Jan 2018, at 14:52, Donny Davis <donny@fortnebula.com = <mailto:donny@fortnebula.com>> wrote: =20 What is the purpose in putting these directives in for the hypervisor?
I have small node where system and data domains located on the same = RAID. Data domains are on separate partitions. These options allow minimise disk access activity.
=20 On Thu, Jan 4, 2018 at 6:46 AM, andreil1 <andreil1@starlett.lv = <mailto:andreil1@starlett.lv>> wrote: Hi ! =20 Is it safe to turn on these options (noatime, nodiratime) in oVirt = node fstab for these mount points? /home / /tmp /var /var/log /var/log/audit =20 Node 4.2 installed on CentOS, not with node DVD. =20 Thanks. =20 _______________________________________________ Users mailing list Users@ovirt.org <mailto:Users@ovirt.org> http://lists.ovirt.org/mailman/listinfo/users = <http://lists.ovirt.org/mailman/listinfo/users> =20
--Apple-Mail=_569F5B4E-58CB-49DD-B127-92B061479BB2 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii <html><head><meta http-equiv=3D"Content-Type" content=3D"text/html; = charset=3Dus-ascii"></head><body style=3D"word-wrap: break-word; = -webkit-nbsp-mode: space; line-break: after-white-space;" class=3D""><meta= http-equiv=3D"Content-Type" content=3D"text/html; charset=3Dus-ascii" = class=3D""><div style=3D"word-wrap: break-word; -webkit-nbsp-mode: = space; line-break: after-white-space;" class=3D""><br class=3D""><div = class=3D""><br class=3D""><blockquote type=3D"cite" class=3D""><div = class=3D"">On 4 Jan 2018, at 14:52, Donny Davis <<a = href=3D"mailto:donny@fortnebula.com" = class=3D"">donny@fortnebula.com</a>> wrote:</div><br = class=3D"Apple-interchange-newline"><div class=3D""><div dir=3D"ltr" = class=3D"">What is the purpose in putting these directives in for the = hypervisor?</div></div></blockquote><div class=3D""><br = class=3D""></div><div class=3D"">I have small node where system and data = domains located on the same RAID.</div><div class=3D"">Data domains are = on separate partitions.</div><div class=3D"">These options allow = minimise disk access activity.</div><br class=3D""><blockquote = type=3D"cite" class=3D""><div class=3D""><div class=3D"gmail_extra"><br = class=3D""><div class=3D"gmail_quote">On Thu, Jan 4, 2018 at 6:46 AM, = andreil1 <span dir=3D"ltr" class=3D""><<a = href=3D"mailto:andreil1@starlett.lv" target=3D"_blank" = class=3D"">andreil1@starlett.lv</a>></span> wrote:<br = class=3D""><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 = .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi !<br class=3D""> <br class=3D""> Is it safe to turn on these options (noatime, nodiratime) in oVirt node = fstab for these mount points?<br class=3D""> /home<br class=3D""> /<br class=3D""> /tmp<br class=3D""> /var<br class=3D""> /var/log<br class=3D""> /var/log/audit<br class=3D""> <br class=3D""> Node 4.2 installed on CentOS, not with node DVD.<br class=3D""> <br class=3D""> Thanks.<br class=3D""> <br class=3D""> ______________________________<wbr class=3D"">_________________<br = class=3D""> Users mailing list<br class=3D""> <a href=3D"mailto:Users@ovirt.org" class=3D"">Users@ovirt.org</a><br = class=3D""> <a href=3D"http://lists.ovirt.org/mailman/listinfo/users" = rel=3D"noreferrer" target=3D"_blank" = class=3D"">http://lists.ovirt.org/<wbr = class=3D"">mailman/listinfo/users</a><br class=3D""> </blockquote></div><br class=3D""></div> </div></blockquote></div><br class=3D""></div></body></html>= --Apple-Mail=_569F5B4E-58CB-49DD-B127-92B061479BB2--
That makes more sense. Have you measured the write load on the disks from just the hypervisor processes. I have included a screen shot from mine, and the load is very low.... in the Kilobytes/sec I am not sure of the implications of changing these parameters, and I do not see an perceivable benefits from doing so. [image: Inline image 1] On Thu, Jan 4, 2018 at 9:51 AM, andreil1 <andreil1@starlett.lv> wrote:
On 4 Jan 2018, at 14:52, Donny Davis <donny@fortnebula.com> wrote:
What is the purpose in putting these directives in for the hypervisor?
I have small node where system and data domains located on the same RAID. Data domains are on separate partitions. These options allow minimise disk access activity.
On Thu, Jan 4, 2018 at 6:46 AM, andreil1 <andreil1@starlett.lv> wrote:
Hi !
Is it safe to turn on these options (noatime, nodiratime) in oVirt node fstab for these mount points? /home / /tmp /var /var/log /var/log/audit
Node 4.2 installed on CentOS, not with node DVD.
Thanks.
_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
On Thu, Jan 4, 2018 at 5:04 PM, Donny Davis <donny@fortnebula.com> wrote:
That makes more sense. Have you measured the write load on the disks from just the hypervisor processes. I have included a screen shot from mine, and the load is very low.... in the Kilobytes/sec
And those are probably the logs, which will be written anyway... Y.
I am not sure of the implications of changing these parameters, and I do not see an perceivable benefits from doing so.
[image: Inline image 1]
On Thu, Jan 4, 2018 at 9:51 AM, andreil1 <andreil1@starlett.lv> wrote:
On 4 Jan 2018, at 14:52, Donny Davis <donny@fortnebula.com> wrote:
What is the purpose in putting these directives in for the hypervisor?
I have small node where system and data domains located on the same RAID. Data domains are on separate partitions. These options allow minimise disk access activity.
On Thu, Jan 4, 2018 at 6:46 AM, andreil1 <andreil1@starlett.lv> wrote:
Hi !
Is it safe to turn on these options (noatime, nodiratime) in oVirt node fstab for these mount points? /home / /tmp /var /var/log /var/log/audit
Node 4.2 installed on CentOS, not with node DVD.
Thanks.
_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Yaniv, If there was a central logging server, would the hypervisors send them there and stop writing to disk (given its setup properly), or does it write them anyway? https://www.ovirt.org/documentation/admin-guide/chap-Log_Files/ On Thu, Jan 4, 2018 at 11:43 AM, Yaniv Kaul <ykaul@redhat.com> wrote:
On Thu, Jan 4, 2018 at 5:04 PM, Donny Davis <donny@fortnebula.com> wrote:
That makes more sense. Have you measured the write load on the disks from just the hypervisor processes. I have included a screen shot from mine, and the load is very low.... in the Kilobytes/sec
And those are probably the logs, which will be written anyway... Y.
I am not sure of the implications of changing these parameters, and I do not see an perceivable benefits from doing so.
[image: Inline image 1]
On Thu, Jan 4, 2018 at 9:51 AM, andreil1 <andreil1@starlett.lv> wrote:
On 4 Jan 2018, at 14:52, Donny Davis <donny@fortnebula.com> wrote:
What is the purpose in putting these directives in for the hypervisor?
I have small node where system and data domains located on the same RAID. Data domains are on separate partitions. These options allow minimise disk access activity.
On Thu, Jan 4, 2018 at 6:46 AM, andreil1 <andreil1@starlett.lv> wrote:
Hi !
Is it safe to turn on these options (noatime, nodiratime) in oVirt node fstab for these mount points? /home / /tmp /var /var/log /var/log/audit
Node 4.2 installed on CentOS, not with node DVD.
Thanks.
_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Both are no brainer to activate (noatime is a superset of nodiratime, see https://lwn.net/Articles/244941/) for every mount point, unless you really know why you need exact atime. If you want to be super-safe, use relatime. You will get not-exact but usable atime, to know if a file was acceded after write. More informations: https://en.wikipedia.org/wiki/Stat_(system_call)#Criticism_of_atime
Le 4 janv. 2018 à 12:46, andreil1 <andreil1@starlett.lv> a écrit :
Hi !
Is it safe to turn on these options (noatime, nodiratime) in oVirt node fstab for these mount points? /home / /tmp /var /var/log /var/log/audit
Node 4.2 installed on CentOS, not with node DVD.
Thanks.
_______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
participants (4)
-
andreil1 -
Donny Davis -
Fabrice Bacchella -
Yaniv Kaul