Re: EVMS 2.5.5 questions
Steve Dobbelstein <[email protected]> Mon, 28 Apr 2008 10:30:49 -0500
| Newsgroups | gmane.linux.evms.devel |
|---|---|
| Message-ID | <OFCD3B2D1F.63B69DB0-ON85257439.0052F74E-86257439.00553854@us.ibm.com> |
--===============0321677342== Content-type: multipart/alternative; Boundary="0__=0ABBFEAADFC171DE8f9e8a93df938690918c0ABBFEAADFC171DE" Content-Disposition: inline --0__=0ABBFEAADFC171DE8f9e8a93df938690918c0ABBFEAADFC171DE Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: quoted-printable [email protected] wrote on 04/26/2008 08:42:59 PM: > Hi all, Hi, Thomas. > Thought I would try again regarding some EVMS questions I have below.= > Any guidance would be hugely appreciated! > > 1) Is there a way, from the EVMS CLI, to find out the % full of a > snapshot? I've run a query:region command on the snapshot region, but= > I'm not getting anything there about the % full. If you are using the EVMS snapshot feature, query:object will display t= he % full as part of the information about the object. I took a quick look through the code for the LVM and LVM2 plug-ins and = did not see any code for returning the % full. I also didn't see any field= s in the headers that would track the % full. I am no LVM expert, but it ma= y be that LVM does not keep track of the % full for a snapshot. > 2) A previous RAID 6 plug-in for EVMS 2.5.3 was posted by an EVMS > community member. Have people been able to use this with success? I'v= e > noticed that it does seem to work..sort of. Often, volumes created on= > RAID 6 regions become deactivated for some reason (don't know why), a= nd > need to be manually reactivated. This does not happen with any other > RAID types. The RAID 6 plug-in that was posted was a good start, but it lacks some = key functionality, which is why it hasn't been checked in to the CVS tree. = For example, it doesn't properly handle the case when a RAID 6 region alrea= dy exists and is active. From what I remember, it does the right thing wh= en creating a brand new RAID 6 region, so a new RAID 6 region should work properly. I am not surprised that it might have issues with an existin= g RAID 6 region. A while back I had started on filling out the RAID 6 plug-in, but that = work has been put on the shelf due to my current responsibilities. :( > 3) Launching EVMS from the CLI gets slower and slower as more objects= > (volumes, regions, etc) are created. Is there any way around this? It= > can take 10 seconds or more to start EVMS from the CLI, if I have 30 > volumes or more. Do you seen the same slowdown if you run evmsn or evmsgui? I suspect s= o since all the user interfaces call the same Engine to do the discovery = of the disk configuration. If you don't see a slowdown in the other user interfaces, then something is slowing down in the CLI itself. Discovery is a complex, iterative process. (Check out engine/discover.= c if you want to know the details. :) ) The discovery process naturally tak= es longer as the number of things (disks, segments, regions, EVMS object, volumes) increases since there are more things to examine. It can also= take longer if the number of things and the way they are structured lea= ds to more iterations. Plus, each examination of a thing results in a rea= d from the disk(s), so the speed of the disk access also plays a part in = the discovery time. The discovery process does keep a cache of sectors rea= d from the disks, which helps speed up the process. > Thank you in advance for any input! Hope this helps. Steve D.= --0__=0ABBFEAADFC171DE8f9e8a93df938690918c0ABBFEAADFC171DE Content-type: text/html; charset=US-ASCII Content-Disposition: inline Content-transfer-encoding: quoted-printable <html><body> <p><tt>[email protected]</tt><tt> wro</tt><tt>te on 04/26/200= 8 08:42:59 PM:<br> <br> > Hi all,</tt><br> <br> <tt>Hi, Thomas.<br> <br> > Thought I would try again regarding some EVMS questions I have bel= ow. <br> > Any guidance would be hugely appreciated!<br> > <br> > 1) Is there a way, from the EVMS CLI, to find out the % full of a<= br> > snapshot? I've run a query:region command on the snapshot region, = but<br> > I'm not getting anything there about the % full.<br> </tt><br> <tt>If you are using the EVMS snapshot feature, query:object will displ= ay the % full as part of the information about the object.</tt><br> <br> <tt>I took a quick look through the code for the LVM and LVM2 plug-ins = and did not see any code for returning the % full. I also didn't = see any fields in the headers that would track the % full. I am n= o LVM expert, but it may be that LVM does not keep track of the % full = for a snapshot.</tt><br> <tt><br> > 2) A previous RAID 6 plug-in for EVMS 2.5.3 was posted by an EVMS<= br> > community member. Have people been able to use this with success? = I've<br> > noticed that it does seem to work..sort of. Often, volumes created= on<br> > RAID 6 regions become deactivated for some reason (don't know why)= , and<br> > need to be manually reactivated. This does not happen with any oth= er<br> > RAID types.<br> </tt><br> <tt>The RAID 6 plug-in that was posted was a good start, but it lacks s= ome key functionality, which is why it hasn't been checked in to the CV= S tree. For example, it doesn't properly handle the case when a R= AID 6 region already exists and is active. From what I remember, = it does the right thing when creating a brand new RAID 6 region, so a n= ew RAID 6 region should work properly. I am not surprised that it= might have issues with an existing RAID 6 region.</tt><br> <br> <tt>A while back I had started on filling out the RAID 6 plug-in, but t= hat work has been put on the shelf due to my current responsibilities. = :(</tt><br> <br> <tt>> 3) Launching EVMS from the CLI gets slower and slower as more = objects<br> > (volumes, regions, etc) are created. Is there any way around this?= It<br> > can take 10 seconds or more to start EVMS from the CLI, if I have = 30<br> > volumes or more.</tt><br> <br> <tt>Do you seen the same slowdown if you run evmsn or evmsgui? I = suspect so since all the user interfaces call the same Engine to do the= discovery of the disk configuration. If you don't see a slowdown= in the other user interfaces, then something is slowing down in the CL= I itself.</tt><br> <br> <tt>Discovery is a complex, iterative process. (Check out engine/= discover.c if you want to know the details. :) ) The discovery pr= ocess naturally takes longer as the number of things (disks, segments, = regions, EVMS object, volumes) increases since there are more things to= examine. It can also take longer if the number of things and the= way they are structured leads to more iterations. Plus, each exa= mination of a thing results in a read from the disk(s), so the speed of= the disk access also plays a part in the discovery time. The dis= covery process does keep a cache of sectors read from the disks, which = helps speed up the process.</tt><br> <tt><br> > Thank you in advance for any input!<br> </tt><br> <tt>Hope this helps.</tt><br> <br> <tt>Steve D.</tt></body></html>= --0__=0ABBFEAADFC171DE8f9e8a93df938690918c0ABBFEAADFC171DE-- --===============0321677342== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. 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