Hi hopefully someone can give me a tip or a better google search query to run. Talking to a guy that has a vmware server setup with 20 guests, all xp. He set them up with a 10gig os drive (c) and a separate 5gig disk image (d) that he configured a 3500-5000 swap. Now my take on this is that since all the disks are on the same physical disk anyway, should we just configured a single 15gig disk image, configure a 5000-5000 (min/max in windows) swap file for windows and be the same? He was saying he thought it was better for performance because otherwise the swap fragments the C:\ drive. He *claims* to have tried this and saw a difference. We plan on moving him from this vmware box with a single physical disk to xen with a 4 drive raid. I really dont want to screw with 2 or 3 or x disk images per virtual machine, management, backups etc. I told him i would like to just give him a single 10+swap+extra = say 20gig single disk image file to use. Comments, input please? _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Nathan Eisenberg
2010-Mar-18 05:23 UTC
RE: [Xen-users] Windows guest, swap space, separate disk?
First and foremost - I believe LVM's are faster than disk images, so if you're looking for performance, I would start there. Best Regards, Nathan Eisenberg> -----Original Message----- > From: xen-users-bounces@lists.xensource.com [mailto:xen-users- > bounces@lists.xensource.com] On Behalf Of Brandon Lamb > Sent: Wednesday, March 17, 2010 3:06 PM > To: xen-users@lists.xensource.com > Subject: [Xen-users] Windows guest, swap space, separate disk? > > Hi hopefully someone can give me a tip or a better google search query > to run. > > Talking to a guy that has a vmware server setup with 20 guests, all > xp. He set them up with a 10gig os drive (c) and a separate 5gig disk > image (d) that he configured a 3500-5000 swap. > > Now my take on this is that since all the disks are on the same > physical disk anyway, should we just configured a single 15gig disk > image, configure a 5000-5000 (min/max in windows) swap file for > windows and be the same? > > He was saying he thought it was better for performance because > otherwise the swap fragments the C:\ drive. He *claims* to have tried > this and saw a difference. > > We plan on moving him from this vmware box with a single physical disk > to xen with a 4 drive raid. I really dont want to screw with 2 or 3 or > x disk images per virtual machine, management, backups etc. I told him > i would like to just give him a single 10+swap+extra = say 20gig > single disk image file to use. > > Comments, input please? > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users > >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Brandon Lamb
2010-Mar-18 05:35 UTC
Re: [Xen-users] Windows guest, swap space, separate disk?
On Wed, Mar 17, 2010 at 10:29 PM, Brandon Lamb <brandonlamb@gmail.com> wrote:> On Wed, Mar 17, 2010 at 10:23 PM, Nathan Eisenberg > <nathan@atlasnetworks.us> wrote: >> First and foremost - I believe LVM''s are faster than disk images, so if you''re looking for performance, I would start there. >> >> Best Regards, >> Nathan Eisenberg >> >> >>> -----Original Message----- >>> From: xen-users-bounces@lists.xensource.com [mailto:xen-users- >>> bounces@lists.xensource.com] On Behalf Of Brandon Lamb >>> Sent: Wednesday, March 17, 2010 3:06 PM >>> To: xen-users@lists.xensource.com >>> Subject: [Xen-users] Windows guest, swap space, separate disk? >>> >>> Hi hopefully someone can give me a tip or a better google search query >>> to run. >>> >>> Talking to a guy that has a vmware server setup with 20 guests, all >>> xp. He set them up with a 10gig os drive (c) and a separate 5gig disk >>> image (d) that he configured a 3500-5000 swap. >>> >>> Now my take on this is that since all the disks are on the same >>> physical disk anyway, should we just configured a single 15gig disk >>> image, configure a 5000-5000 (min/max in windows) swap file for >>> windows and be the same? > > Im actually running the disk images on top of lvm partitions, but this > particular use case requires file based disks for our customer, > basically a reseller of our service. He wants to offer HIS customers > the ability that if they blow up their windows xp box, he can just > relaunch the vm pointing to the backup disk image. > > To do this, it seemed much easier to be able to do a cp live-disk.img > backup-disk.img versus doing a dd or ? to create a backup. > > Hm actually does anyone have any input on that? is "cp file1 file2" > faster than a "dd if=/dev/volumes/file1 of=/dev/volumes/file2"? >Although a problem with the all lvm block level method is ok so when we create a manual backup of the live disk, we would do dd if=/dev/volumes/cust1-live of=/dev/volumes/cust1-backup This only will happen once in a great while, after major software changes and such. But now we also want a remote backup machine to have a DR copy of cust1-backup, so disk space wise we would have to have (size of cust1-live) + (size of cust1-backup) + (size of dd if=/dev/volumes/cust1-backup of=/backups/cust1.img) Hah hope that is not over complicating it but not sure how else you would handle that _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Brandon Lamb
2010-Mar-18 05:36 UTC
Re: [Xen-users] Windows guest, swap space, separate disk?
On Wed, Mar 17, 2010 at 10:23 PM, Nathan Eisenberg <nathan@atlasnetworks.us> wrote:> First and foremost - I believe LVM''s are faster than disk images, so if you''re looking for performance, I would start there. > > Best Regards, > Nathan Eisenberg >Im actually running the disk images on top of lvm partitions, but this particular use case requires file based disks for our customer, basically a reseller of our service. He wants to offer HIS customers the ability that if they blow up their windows xp box, he can just relaunch the vm pointing to the backup disk image. To do this, it seemed much easier to be able to do a cp live-disk.img backup-disk.img versus doing a dd or ? to create a backup. Hm actually does anyone have any input on that? is "cp file1 file2" faster than a "dd if=/dev/volumes/file1 of=/dev/volumes/file2"? _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Dustin Henning
2010-Mar-18 12:58 UTC
RE: [Xen-users] Windows guest, swap space, separate disk?
If swap is disable, a drive is defragmented, and swap is created (say 5000-5000 as you suggest), it should be one contiguous file. If it is created 3500-5000 and eventually expands, then the swap will have fragments, the number would depend on the fragmentation of the drive. That having been said, I would argue that it is silly to make swap on a different virtual drive where the two drives are the same physical drive. Any OS performance difference he saw was a) due to his practices b) coincidental due to the location of the files in question, or c) pure placebo effect. That having been said, if the user only wants to back up the drive images and isn''t worried about the swap images, having a separate swap image suddenly means an extra 5 GiB that doesn''t need copied every time there is a backup performed, that could certainly constitute a performance difference (all things being equal, copying a 20 GiB file will take twice as long as copying a 10GiB file). Dustin -----Original Message----- From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Brandon Lamb Sent: Wednesday, March 17, 2010 18:06 To: xen-users@lists.xensource.com Subject: [Xen-users] Windows guest, swap space, separate disk? Hi hopefully someone can give me a tip or a better google search query to run. Talking to a guy that has a vmware server setup with 20 guests, all xp. He set them up with a 10gig os drive (c) and a separate 5gig disk image (d) that he configured a 3500-5000 swap. a Now my take on this is that since all the disks are on the same physical disk anyway, should we just configured a single 15gig disk image, configure a 5000-5000 (min/max in windows) swap file for windows and be the same? He was saying he thought it was better for performance because otherwise the swap fragments the C:\ drive. He *claims* to have tried this and saw a difference. We plan on moving him from this vmware box with a single physical disk to xen with a 4 drive raid. I really dont want to screw with 2 or 3 or x disk images per virtual machine, management, backups etc. I told him i would like to just give him a single 10+swap+extra = say 20gig single disk image file to use. Comments, input please? _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Dustin Henning
2010-Mar-18 13:02 UTC
RE: [Xen-users] Windows guest, swap space, separate disk?
Assuming the file and or image are the same size, I would expect DD to be faster (especially if tuned with the bs= parameted). However, theories don''t always work out in real life, and this wouldn''t necessarily be true depending on the type of copy (for instance mounting and using ntfsclone wouldn''t necessarily be copying the full 10 or 20 GiB), so testing the difference might not be a bad idea. Also, you should search the net for a blocksync script, someone wrote one in python once, its end effect was similar to dd, but it somehow only copied changed blocks, so that might make copying between images faster than copying between files (even with ntfsclone or something). Dustin -----Original Message----- From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Brandon Lamb Sent: Thursday, March 18, 2010 01:36 To: xen-users@lists.xensource.com Subject: Re: [Xen-users] Windows guest, swap space, separate disk? On Wed, Mar 17, 2010 at 10:23 PM, Nathan Eisenberg <nathan@atlasnetworks.us> wrote:> First and foremost - I believe LVM''s are faster than disk images, so if you''re looking for performance, I would start there. > > Best Regards, > Nathan Eisenberg >Im actually running the disk images on top of lvm partitions, but this particular use case requires file based disks for our customer, basically a reseller of our service. He wants to offer HIS customers the ability that if they blow up their windows xp box, he can just relaunch the vm pointing to the backup disk image. To do this, it seemed much easier to be able to do a cp live-disk.img backup-disk.img versus doing a dd or ? to create a backup. Hm actually does anyone have any input on that? is "cp file1 file2" faster than a "dd if=/dev/volumes/file1 of=/dev/volumes/file2"? _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Dustin Henning
2010-Mar-18 13:10 UTC
RE: [Xen-users] Windows guest, swap space, separate disk?
Actually, in addition to (a), (b), and (c) below, I suppose it might be possible that there would be a notable performance difference due to the performance loss caused by using loop vs phy (perhaps the two separate loops can be used at the same time where to negate the lost performance to some degree). In that case, having multiple files might be helpful, but one image would be acceptable where the procedure I previously mentioned is used for setting up swap. That having been said, again, this would still mean the 5 GiB of swap has to be backed up as well if it wouldn''t have been otherwise. Dustin -----Original Message----- From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Dustin Henning Sent: Thursday, March 18, 2010 08:59 To: ''Brandon Lamb''; xen-users@lists.xensource.com Subject: RE: [Xen-users] Windows guest, swap space, separate disk? If swap is disable, a drive is defragmented, and swap is created (say 5000-5000 as you suggest), it should be one contiguous file. If it is created 3500-5000 and eventually expands, then the swap will have fragments, the number would depend on the fragmentation of the drive. That having been said, I would argue that it is silly to make swap on a different virtual drive where the two drives are the same physical drive. Any OS performance difference he saw was a) due to his practices b) coincidental due to the location of the files in question, or c) pure placebo effect. That having been said, if the user only wants to back up the drive images and isn''t worried about the swap images, having a separate swap image suddenly means an extra 5 GiB that doesn''t need copied every time there is a backup performed, that could certainly constitute a performance difference (all things being equal, copying a 20 GiB file will take twice as long as copying a 10GiB file). Dustin -----Original Message----- From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Brandon Lamb Sent: Wednesday, March 17, 2010 18:06 To: xen-users@lists.xensource.com Subject: [Xen-users] Windows guest, swap space, separate disk? Hi hopefully someone can give me a tip or a better google search query to run. Talking to a guy that has a vmware server setup with 20 guests, all xp. He set them up with a 10gig os drive (c) and a separate 5gig disk image (d) that he configured a 3500-5000 swap. a Now my take on this is that since all the disks are on the same physical disk anyway, should we just configured a single 15gig disk image, configure a 5000-5000 (min/max in windows) swap file for windows and be the same? He was saying he thought it was better for performance because otherwise the swap fragments the C:\ drive. He *claims* to have tried this and saw a difference. We plan on moving him from this vmware box with a single physical disk to xen with a 4 drive raid. I really dont want to screw with 2 or 3 or x disk images per virtual machine, management, backups etc. I told him i would like to just give him a single 10+swap+extra = say 20gig single disk image file to use. Comments, input please? _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Brandon Lamb
2010-Mar-18 18:18 UTC
Re: [Xen-users] Windows guest, swap space, separate disk?
On Thu, Mar 18, 2010 at 6:10 AM, Dustin Henning <Dustin.Henning@prd-inc.com> wrote:> Actually, in addition to (a), (b), and (c) below, I suppose it might be possible that there would be a notable performance difference due to the performance loss caused by using loop vs phy (perhaps the two separate loops can be used at the same time where to negate the lost performance to some degree). In that case, having multiple files might be helpful, but one image would be acceptable where the procedure I previously mentioned is used for setting up swap. That having been said, again, this would still mean the 5 GiB of swap has to be backed up as well if it wouldn''t have been otherwise. > Dustin > > -----Original Message----- > From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Dustin Henning > Sent: Thursday, March 18, 2010 08:59 > To: ''Brandon Lamb''; xen-users@lists.xensource.com > Subject: RE: [Xen-users] Windows guest, swap space, separate disk? > > If swap is disable, a drive is defragmented, and swap is created (say 5000-5000 as you suggest), it should be one contiguous file. If it is created 3500-5000 and eventually expands, then the swap will have fragments, the number would depend on the fragmentation of the drive. That having been said, I would argue that it is silly to make swap on a different virtual drive where the two drives are the same physical drive. Any OS performance difference he saw was a) due to his practices b) coincidental due to the location of the files in question, or c) pure placebo effect. That having been said, if the user only wants to back up the drive images and isn''t worried about the swap images, having a separate swap image suddenly means an extra 5 GiB that doesn''t need copied every time there is a backup performed, that could certainly constitute a performance difference (all things being equal, copying a 20 GiB file will take twice as long as copying a 10GiB file). > Dustin > > -----Original Message----- > From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Brandon Lamb > Sent: Wednesday, March 17, 2010 18:06 > To: xen-users@lists.xensource.com > Subject: [Xen-users] Windows guest, swap space, separate disk? > > Hi hopefully someone can give me a tip or a better google search query to run. > > Talking to a guy that has a vmware server setup with 20 guests, all > xp. He set them up with a 10gig os drive (c) and a separate 5gig disk > image (d) that he configured a 3500-5000 swap. > a > Now my take on this is that since all the disks are on the same > physical disk anyway, should we just configured a single 15gig disk > image, configure a 5000-5000 (min/max in windows) swap file for > windows and be the same? > > He was saying he thought it was better for performance because > otherwise the swap fragments the C:\ drive. He *claims* to have tried > this and saw a difference. > > We plan on moving him from this vmware box with a single physical disk > to xen with a 4 drive raid. I really dont want to screw with 2 or 3 or > x disk images per virtual machine, management, backups etc. I told him > i would like to just give him a single 10+swap+extra = say 20gig > single disk image file to use. > > Comments, input please?Wow very nice reply thank you, gives me more to think about and very good point on not having to backup an extra 5 gigs, hmmm _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users