From: <pa...@bo...> - 2004-03-20 05:24:40
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Hello ! What I have to do for upgrade the disk space for a virtual server? For example, I have a root_fs with 2 GB and 5 customers using it. So, I have 5 cow-files with 2 GB each, right ? And, I need upgrade my customer number 3, from 2 GB to 4 GB. And the others customers must continue having your 2 GB each. What I have to do exactly ? Thanks! Pedro |
From: Goetz B. <bo...@bl...> - 2004-03-22 17:04:28
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On Sat, Mar 20 '04 at 02:25, pa...@bo... wrote: > What I have to do for upgrade the disk space for a virtual server? > > For example, I have a root_fs with 2 GB and 5 customers using it. > > So, I have 5 cow-files with 2 GB each, right ? I would not use cow files, but if you did, that would be the case (the cow files would be sparse) > > And, I need upgrade my customer number 3, from 2 GB to 4 GB. > And the others customers must continue having your 2 GB each. > What I have to do exactly ? You can't. But why are people so into using cow files in the first place? Disks are rote cheap (less then the size (in GB) in euro for disks with less then about 200GB) Just give every UML a couple of disk images: - root - var - tmp - home with proper sizes (1G, .5G, 256M, 1G come to mind) than you can resize what you have to resize. You could even cow the root image (COWing the other images does not make sence). -- /"\ Goetz Bock at blacknet dot de -- secure mobile Linux everNETting \ / (c) 2003 as GNU FDL 1.1 X [ 1. Use descriptive subjects - 2. Edit a reply for brevity - ] / \ [ 3. Reply to the list - 4. Read the archive *before* you post ] |
From: Steven P. <st...@si...> - 2004-03-22 18:48:19
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On Mon, Mar 22, 2004 at 05:55:47PM +0100, Goetz Bock wrote: > But why are people so into using cow files in the first place? In my case, it is because it is so simple (and fast) to create a COW file. New UMLs can be started in literally a few seconds. Steve -- Steven Pritchard - K&S Pritchard Enterprises, Inc. Email: st...@ks... http://www.kspei.com/ Phone: (618)398-7360 Mobile: (618)567-7320 |
From: Jeff D. <jd...@ad...> - 2004-03-22 19:13:45
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bo...@bl... said: > But why are people so into using cow files in the first place? Because they save a lot of host memory. Using COW, each page of the backing file is present once in the host page cache (plus once for the page cache of each UML using it). Without COW, that would be one copy per UML (and again once per UML page cache). It also makes booting UMLs after the first one faster since the backing file data is already in host memory and doesn't need to be copied from disk. Jeff |
From: Dan L. <ar...@co...> - 2004-03-22 22:24:32
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If you are using SCSI disks, the price is not so cheap. Even more so if you are using RAID'ed SCSI disks. Space on a server is not as cheap as a 'home' machine, or a low-end IDE set. --Dan Goetz Bock wrote: >On Sat, Mar 20 '04 at 02:25, pa...@bo... wrote: > > >>What I have to do for upgrade the disk space for a virtual server? >> >>For example, I have a root_fs with 2 GB and 5 customers using it. >> >>So, I have 5 cow-files with 2 GB each, right ? >> >> >I would not use cow files, but if you did, that would be the case (the >cow files would be sparse) > > >>And, I need upgrade my customer number 3, from 2 GB to 4 GB. >>And the others customers must continue having your 2 GB each. >>What I have to do exactly ? >> >> >You can't. > >But why are people so into using cow files in the first place? > >Disks are rote cheap (less then the size (in GB) in euro for disks >with less then about 200GB) > >Just give every UML a couple of disk images: >- root >- var >- tmp >- home >with proper sizes (1G, .5G, 256M, 1G come to mind) than you can resize >what you have to resize. You could even cow the root image (COWing the >other images does not make sence). > > ----------- This email message and any attachment may contain Confidential or Protected Health Information. If you are not the intended recipient please notify us immediately at 480-648-4545 and delete the message. |
From: BlaisorBlade <bla...@ya...> - 2004-03-23 01:07:13
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Alle 06:25, sabato 20 marzo 2004, pa...@bo... ha scritto: > Hello ! > > What I have to do for upgrade the disk space for a virtual server? > > For example, I have a root_fs with 2 GB and 5 customers using it. > > So, I have 5 cow-files with 2 GB each, right ? The cow files can *grow up to* the size of the backing file, and no more. > And, I need upgrade my customer number 3, from 2 GB to 4 GB. > > And the others customers must continue having your 2 GB each. So to increase the space for only one customer you need to use a different backing file for the "big" customer (i.e. you take that one and expand it). The command should be something like (please backup your file before): dd if=/dev/zero of=root_fs count=1 skip=<the new size in 1k block units - 1> i.e., to obtain 4 giga, since 4mega is 4194304: dd if=/dev/zero of=root_fs count=1 skip=4194303 This will increase the size of the file while preserving its datas; then you must use resize2fs or resize_reiserfs to update filesystem metadata for the new size. Or (a lot simpler) just use a second UBD device for customer number 2; he will then mount both /dev/ubd0 and /dev/ubd1 inside his server and enjoy the new space. -- Paolo Giarrusso, aka Blaisorblade Linux registered user n. 292729 |