[SLE] Is there any real purpose for hald on a server-only system?
I've quickly had a look at what hal is all about, and it seems to me that it's primarily for making things easier for users on a desktop, whereas it makes little or no sense on a server system? Have I overlooked anything? /Per Jessen, Zürich PS: debian has some man-pages for the hal-stuff, but SUSE doesn't distribute any? -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
Per Jessen skrev:
I've quickly had a look at what hal is all about, and it seems to me that it's primarily for making things easier for users on a desktop, whereas it makes little or no sense on a server system? Have I overlooked anything?
/Per Jessen, Zürich PS: debian has some man-pages for the hal-stuff, but SUSE doesn't distribute any?
I use it for mounting iSCSI volumes at boot on my servers.. Since the volume doesn't show up until network is up, and the initiator is started, HAL does this work and mounts by volume uuid as soon as it shows up. -- Anders Norrbring Norrbring Consulting -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
Anders Norrbring wrote:
Per Jessen skrev:
I've quickly had a look at what hal is all about, and it seems to me that it's primarily for making things easier for users on a desktop, whereas it makes little or no sense on a server system? Have I overlooked anything?
I use it for mounting iSCSI volumes at boot on my servers.. Since the volume doesn't show up until network is up, and the initiator is started, HAL does this work and mounts by volume uuid as soon as it shows up.
Interesting application. I guess my question should have been more - is there anything in a vanilla SUSE server installation that _requires_ hald? /Per Jessen, Zürich -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
On Saturday 01 July 2006 09:14, Per Jessen wrote:
Anders Norrbring wrote:
Per Jessen skrev:
I've quickly had a look at what hal is all about, and it seems to me that it's primarily for making things easier for users on a desktop, whereas it makes little or no sense on a server system? Have I overlooked anything?
I use it for mounting iSCSI volumes at boot on my servers.. Since the volume doesn't show up until network is up, and the initiator is started, HAL does this work and mounts by volume uuid as soon as it shows up.
Interesting application. I guess my question should have been more - is there anything in a vanilla SUSE server installation that _requires_ hald?
/Per Jessen, Zürich
I've been thinking the same thing and just turned it off on my server. Will let you know if anything untowards hap....... pens -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 The Saturday 2006-07-01 at 12:41 +0200, Per Jessen wrote:
I've quickly had a look at what hal is all about, and it seems to me that it's primarily for making things easier for users on a desktop, whereas it makes little or no sense on a server system? Have I overlooked anything?
I understand that now everything in /dev is created dynamically by the udev system, and udev depends on hal to know what devices are present in the system to create the nodes. So the answer is that hald is required, yes - unless you dissable udev as well, and go for a completely static /dev tree. The details, I do not know. - -- Cheers, Carlos Robinson -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (GNU/Linux) Comment: Made with pgp4pine 1.76 iD8DBQFEpn2dtTMYHG2NR9URAhprAJ468lmNNRs7/bNiylByxgcAwIl2LgCgix+c Lfwo5RDQdV9CkOH/qW7ua8o= =kBF2 -----END PGP SIGNATURE----- -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
Carlos E. R. wrote:
I understand that now everything in /dev is created dynamically by the udev system, and udev depends on hal to know what devices are present in the system to create the nodes.
That would obviously make hal a hard requirement.
So the answer is that hald is required, yes - unless you dissable udev as well, and go for a completely static /dev tree.
No, udev suites me just fine. :-) However, what you're saying doesn't sound quite right - from studying the HAL website, HAL seems to be about e.g. hotpluggable devices, typically USB, Firewire but I guess also potentially anything else that's hotpluggable. On a typical server the hotpluggable devices are the powersupplies, the CPUs, the PCI-cards and of course the disks. Do you know if HAL gets involved here too?? /Per Jessen, Zürich -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
On Saturday 01 July 2006 12:00, Per Jessen wrote:
Carlos E. R. wrote:
I understand that now everything in /dev is created dynamically by the udev system, and udev depends on hal to know what devices are present in the system to create the nodes.
That would obviously make hal a hard requirement.
So the answer is that hald is required, yes - unless you dissable udev as well, and go for a completely static /dev tree.
No, udev suites me just fine. :-)
However, what you're saying doesn't sound quite right - from studying the HAL website, HAL seems to be about e.g. hotpluggable devices, typically USB, Firewire but I guess also potentially anything else that's hotpluggable. On a typical server the hotpluggable devices are the powersupplies, the CPUs, the PCI-cards and of course the disks. Do you know if HAL gets involved here too??
/Per Jessen, Zürich
Well the discussion got me curious and as I said in a previous mail, I had shut down haldaemon as an experiment. So I thought to myself.... why not boot the server and see what happens, But first lets disable HAL so it won't come up at boot time. Nope.... here's where you can see what shutting down HAL does.... All you have to do is to go into YAST2--> System services and try to disable HAL. You will get a dialog which tells you what other services must also be shut down because they depend on HAL. Many, many, of which network, fetchmail, vsftpd, named, cron, xinetd, ssh, dhcpd .... ad nauseum.... But the first in that list is enough for me.... :-) -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
Bruce Marshall wrote:
Well the discussion got me curious and as I said in a previous mail, I had shut down haldaemon as an experiment.
So I thought to myself.... why not boot the server and see what happens, But first lets disable HAL so it won't come up at boot time.
Nope.... here's where you can see what shutting down HAL does....
All you have to do is to go into YAST2--> System services and try to disable HAL. You will get a dialog which tells you what other services must also be shut down because they depend on HAL. Many, many, of which network, fetchmail, vsftpd, named, cron, xinetd, ssh, dhcpd .... ad nauseum....
Interesting experiment - I'm getting tempted to do one myself. I do wonder where those dependencies came from though - if you check for init scripts dependent on 'haldaemon' - which is what hald provides - only 'powersaved', 'sane-dev' and 'network' have such a dependency. /Per Jessen, Zürich -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
Per Jessen wrote:
Interesting experiment - I'm getting tempted to do one myself.
Which I've just done: I did an "insserv -r haldaemon" which complained about 'network" depending on 'haldaemon'. So I did an "insserv -rf haldaemon" instead and rebooted the box. Not having hald running doesn't seem to make much of difference. /Per Jessen, Zürich -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
On Saturday 01 July 2006 13:17, Per Jessen wrote:
Per Jessen wrote:
Interesting experiment - I'm getting tempted to do one myself.
Which I've just done:
I did an "insserv -r haldaemon" which complained about 'network" depending on 'haldaemon'. So I did an "insserv -rf haldaemon" instead and rebooted the box. Not having hald running doesn't seem to make much of difference.
This is a Good Thing (tm) right? -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
Bruce Marshall wrote:
On Saturday 01 July 2006 13:17, Per Jessen wrote:
Per Jessen wrote:
Interesting experiment - I'm getting tempted to do one myself.
Which I've just done:
I did an "insserv -r haldaemon" which complained about 'network" depending on 'haldaemon'. So I did an "insserv -rf haldaemon" instead and rebooted the box. Not having hald running doesn't seem to make much of difference.
This is a Good Thing (tm) right?
I think so, but this server doesn't do much of anything - it's just a testbox for now - so I'll have to wait and see. I'm wondering why the 'network' init-script would have a haldaemon dependency? USB-stuff? PCMCIA? /Per Jessen, Zürich -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
On Saturday 01 July 2006 14:38, Per Jessen wrote:
This is a Good Thing (tm) right?
I think so, but this server doesn't do much of anything - it's just a testbox for now - so I'll have to wait and see. I'm wondering why the 'network' init-script would have a haldaemon dependency? USB-stuff? PCMCIA?
Well, I just did the insserv to remove it and the reboot is in progress. This server is my firewall and gateway and also an email server... Should be sufficient to test it. And it's up and running just fine it seems. -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 The Saturday 2006-07-01 at 19:17 +0200, Per Jessen wrote:
Interesting experiment - I'm getting tempted to do one myself.
Which I've just done:
I did an "insserv -r haldaemon" which complained about 'network" depending on 'haldaemon'. So I did an "insserv -rf haldaemon" instead and rebooted the box. Not having hald running doesn't seem to make much of difference.
It depends on which version of SuSE you are running; for 10.1 it would be much different, I think. It is not simply hotpluggable things. Try the command "lshal", and you will see that it reports on fixed hardisks and partitions, video, chipset, ethernet.... everything. And I tried with 9.3, as I say, with 10.1 it is far more integrated, or so I have been told. - -- Cheers, Carlos Robinson -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (GNU/Linux) Comment: Made with pgp4pine 1.76 iD8DBQFEpxGStTMYHG2NR9URAqo9AKCTA04vUme/zbPTv3XANCmF+jxyaQCgioJz 8eDwWpLmzTrHkAidRcC1b/o= =tayB -----END PGP SIGNATURE----- -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
On Saturday 01 July 2006 20:21, Carlos E. R. wrote:
The Saturday 2006-07-01 at 19:17 +0200, Per Jessen wrote:
Interesting experiment - I'm getting tempted to do one myself.
Which I've just done:
I did an "insserv -r haldaemon" which complained about 'network" depending on 'haldaemon'. So I did an "insserv -rf haldaemon" instead and rebooted the box. Not having hald running doesn't seem to make much of difference.
It depends on which version of SuSE you are running; for 10.1 it would be much different, I think.
It is not simply hotpluggable things. Try the command "lshal", and you will see that it reports on fixed hardisks and partitions, video, chipset, ethernet.... everything. And I tried with 9.3, as I say, with 10.1 it is far more integrated, or so I have been told.
I turned HAL off on my server which is running 10.1. So far nothing has changed. -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
Carlos E. R. wrote:
The Saturday 2006-07-01 at 19:17 +0200, Per Jessen wrote:
Interesting experiment - I'm getting tempted to do one myself.
Which I've just done:
I did an "insserv -r haldaemon" which complained about 'network" depending on 'haldaemon'. So I did an "insserv -rf haldaemon" instead and rebooted the box. Not having hald running doesn't seem to make much of difference.
It depends on which version of SuSE you are running; for 10.1 it would be much different, I think.
This is a 10.1 system :-)
It is not simply hotpluggable things. Try the command "lshal", and you will see that it reports on fixed hardisks and partitions, video, chipset, ethernet.... everything.
Yeah, I did notice that, but that doesn't necessarily mean hald does anything for all of that. Still, that is the reason I brought up the question. Anders' example of using hald in a context of iSCSI was quite interesting, and there might very well be other such examples. BTW, it's not that I have any particular dislike of hald, I just wanted to know what it does for me, and it didn't seem to do much for a non-desktop system. /Per Jessen, Zürich -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 The Sunday 2006-07-02 at 10:20 +0200, Per Jessen wrote:
It is not simply hotpluggable things. Try the command "lshal", and you will see that it reports on fixed hardisks and partitions, video, chipset, ethernet.... everything.
Yeah, I did notice that, but that doesn't necessarily mean hald does anything for all of that. Still, that is the reason I brought up the question. Anders' example of using hald in a context of iSCSI was quite interesting, and there might very well be other such examples.
Well, usb, firewire, scanners, etc, are obvious examples. Hardisk partitions or video card are less clear.
BTW, it's not that I have any particular dislike of hald, I just wanted to know what it does for me, and it didn't seem to do much for a non-desktop system.
Not being a linux developper, I don't know to what extent the integration has reached. I heard that the intention was to use that "hardware abstraction layer" as that, as a method to know everything available on the system in order to decide what needs to be created in /dev. Its difficult to keep track of these things unless someone in the know speaks up... It may be that udev doesn't require hald to be running. Or it is compiled in... I don't know. - -- Cheers, Carlos Robinson -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (GNU/Linux) Comment: Made with pgp4pine 1.76 iD8DBQFEp6J/tTMYHG2NR9URAgnDAJsHz7/7PseW99+T3PjKvjhQTTRZ0wCdGXOt VZScCQTrdNzlKFELnwLwsF8= =SnzF -----END PGP SIGNATURE----- -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
On 7/1/06 6:41 AM, "Per Jessen"
I've quickly had a look at what hal is all about, and it seems to me that it's primarily for making things easier for users on a desktop, whereas it makes little or no sense on a server system? Have I overlooked anything?
I worked through the "what requires" RPM option to figure this out with 10.0, and it turned out that on a basic server install (text-only, plus a couple of utils, apache, and php) the only thing that needed hald was powersaved. In that particular application, I didn't want powersaved running anyway, so I just removed it, disabled hald, and everything has been running for months without issue. That said, I have no USB devices, no firewire devices, no iSCSI or other SAN, basically nothing fancy at all. Not sure if that holds true for 10.1, but that's my experience with 10.0. I would give it a good bit of QA before experimenting in a production environment, though... (Also, whatever you end up doing, pay attention to the system clock. What made me disable powersaved was clock skew related to freq scaling...there was some weirdness there in 9.3 and 10.0, don't know yet if it's gone in 10.1) -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
Ian Marlier wrote:
I worked through the "what requires" RPM option to figure this out with 10.0, and it turned out that on a basic server install (text-only, plus a couple of utils, apache, and php) the only thing that needed hald was powersaved. In that particular application, I didn't want powersaved running anyway, so I just removed it, disabled hald, and everything has been running for months without issue.
Thanks Ian, that is exactly what I wanted to hear. And I have no need for powersaved either.
That said, I have no USB devices, no firewire devices, no iSCSI or other SAN, basically nothing fancy at all.
Pretty much the same here, although I might be looking at running a SAN over fibre.
Not sure if that holds true for 10.1, but that's my experience with 10.0. I would give it a good bit of QA before experimenting in a production environment, though...
Absolutely.
(Also, whatever you end up doing, pay attention to the system clock. What made me disable powersaved was clock skew related to freq scaling...there was some weirdness there in 9.3 and 10.0, don't know yet if it's gone in 10.1)
I run NTP everywhere. /Per Jessen, Zürich -- Check the headers for your unsubscription address For additional commands send e-mail to suse-linux-e-help@suse.com Also check the archives at http://lists.suse.com Please read the FAQs: suse-linux-e-faq@suse.com
participants (5)
-
Anders Norrbring -
Bruce Marshall -
Carlos E. R. -
Ian Marlier -
Per Jessen