<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> </head> <body bgcolor="#ffffff" text="#000000"> <font size="+1">Hello all,<br> <br> I've been 'away' from all things Linux in general and RH in particular for a long while, so I've got some catching up to do ;)<br> <br> I've got a pretty fair collection of tabs reading on LVM and how it works and why its such a great thing for enterprise use, etc., being able to add storage to the pool and all that. LVM was just kind of catching on when I moved away from Linux for a while, so it's a little odd to me. <br> <br> What I have currently is an older PC that I'm hoping to use as a home server / occasional 'workstation'. One 13GB main drive, and a 500GB drive for network storage. The default install in CentOS 5.4 seems to want to just lump everything together in one big volume. I was thinking perhaps it'd be better to have two volumes (or pools, like I said - still learning and not entirely confident of the lingo involved)... one for the main or 'system' drive (the 13GB one with / mounted on it), and another one for the 500GB sata drive on it - so if I want to add another big drive for more storage, it'd go under that group, ready to serve up storage to the WLAN.<br> <br> Is there anything particularly 'wrong' with that layout, as compared to the default 'everything in one logical volume' approach that the installer utilized?<br> <br> Another question... I thought the filesystem hierarchy standard outlined a /srv directory for services provided... like storage space, etc. but it didn't seem to be listed as one of the available mount points when I was fiddling with the partitioning segment of the installer, debating whether to over ride it or let it do its thing. There was of course the option to enter my own mount point... but in the end I opted to wait and see if there was maybe a reason why RH/CentOS doesn't seem to include this in the default setup? Is there a more traditionally suitable location for things to go under? 99% of the use of this machine is going to be providing storage space to the various laptops and PCs in the house, so primarily as a Samba server...<br> <br> Thanks,<br> <br> Monte<br> </font> </body> </html>
On Sat, 2009-11-07 at 22:22 -0800, Monte Milanuk wrote:> Hello all, > > I've been 'away' from all things Linux in general and RH in particular > for a long while, so I've got some catching up to do ;) > > I've got a pretty fair collection of tabs reading on LVM and how it > works and why its such a great thing for enterprise use, etc., being > able to add storage to the pool and all that. LVM was just kind of > catching on when I moved away from Linux for a while, so it's a little > odd to me. > > What I have currently is an older PC that I'm hoping to use as a home > server / occasional 'workstation'. One 13GB main drive, and a 500GB > drive for network storage. The default install in CentOS 5.4 seems to > want to just lump everything together in one big volume. I was > thinking perhaps it'd be better to have two volumes (or pools, like I > said - still learning and not entirely confident of the lingo > involved)... one for the main or 'system' drive (the 13GB one with / > mounted on it), and another one for the 500GB sata drive on it - so if > I want to add another big drive for more storage, it'd go under that > group, ready to serve up storage to the WLAN. > > Is there anything particularly 'wrong' with that layout, as compared > to the default 'everything in one logical volume' approach that the > installer utilized?There won't be any issue in doing this. The installer just tries to make things easier by creating one big volume group. I'd say that in some ways seperating the two disks in this case would actually be better. :) With both drives in one big volume group, failure of one drive will (most likely) cause both the OS and data to be lost. Seperating them will mean that if your OS drive fails you can replace the dead drive, reinstall CentOS (or restore from a backup), and your data will be accessible again. Of course you would still have to create regular backups, or you would still be in a very unhappy situation if the data drive fails but it would still save you a lot of headache in the event that you encounter a situation in which only the OS drive fails. :) Regards Hamzah -- M. Hamzah Khan RedHat Certified Engineer Number: 804005539516829 Email: hamzah at hamzahkhan.com URL: http://www.hamzahkhan.com Mobile: +44 (0)7525663951 -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 198 bytes Desc: This is a digitally signed message part URL: <http://lists.centos.org/pipermail/centos/attachments/20091108/79c5debf/attachment-0003.sig>
M. Hamzah Khan wrote:> There won't be any issue in doing this. The installer just tries to make > things easier by creating one big volume group. > > I'd say that in some ways seperating the two disks in this case would > actually be better. :) >My last 'serious' experience with Linux was some years ago... mostly before LVM really became popular (it was out and about, but mostly only in SuSE). I'm still 'stuck' in the mind set of a main drive or partition for things like '/', possibly even /boot, /var, /usr, etc. and then keeping /home separate - mainly so the user data in /home survives upgrades and updates and such ;)> With both drives in one big volume group, failure of one drive will > (most likely) cause both the OS and data to be lost. >There in lies some of my confusion with this subject; correct me if I'm wrong in my understanding here: with LVM, I can keep adding more drives to a 'pool' and expand the size of the 'volume' that the OS sees available to it... but if any drive in that volume fails, I'd probably lose everything stored in that volume?!? Sounds like a somewhat risky business to me, unless you *really* needed a storage volume that big that you had to span multiple drives to do so.> Seperating them will mean that if your OS drive fails you can replace > the dead drive, reinstall CentOS (or restore from a backup), and your > data will be accessible again. >Kind of what I had in mind, as the 13GB drive is much older (circa 2005, if its the original one put in when the previous owner built the box from a bare-bones kit) than the 500GB SATA drive (earlier this year, when I stuck it in there) so if I had to put money on one failing before the other... ;)
On Sun, Nov 8, 2009 at 1:22 AM, Monte Milanuk <memilanuk at gmail.com> wrote: [...]> > What I have currently is an older PC that I'm hoping to use as a home server > / occasional 'workstation'.? One 13GB main drive, and a 500GB drive for > network storage.? The default install in CentOS 5.4 seems to want to just > lump everything together in one big volume.? I was thinking perhaps it'd be > better to have two volumes (or pools, like I said - still learning and not > entirely confident of the lingo involved)... one for the main or 'system' > drive (the 13GB one with / mounted on it), and another one for the 500GB > sata drive on it - so if I want to add another big drive for more storage, > it'd go under that group, ready to serve up storage to the WLAN. > > Is there anything particularly 'wrong' with that layout, as compared to the > default 'everything in one logical volume' approach that the installer > utilized?Nothing wrong with it and I would certainly recommend that you separate the data volumes from the OS volumes. In the very least it will allow you to move the data drive to another system and bring it online. And yes, if you lose a single drive in a non-RAIDed LVM group, you can lose the whole volume. If there's data that is absolutely critical, you can put it on an LVM RAID or at least mirror it. This said, having even a single drive in an LVM VG can be beneficial. For example: 1) Adding space is as simple as adding another drive to the VG. 2) If you later want to mirror the drive, just add another drive and mirror the LV. 3) If you run out of space, you can add a larger drive then migrate the PVs from the original drive to the new, larger drive. This also works if the original drive is starting to fail. 4) You can create LV snapshots easily which is very useful for backups.