Others can chime in - but the biggest reason I find for an LVM 'going bad' - is that one of the disks that make up the LVM isn't online. Someone forgot to update zipl.conf or modprobe.conf and didn't do a zipl or mkinitrd when they added the disk - so next time it boots - it's missing one of the LVM disks.
Or - someone really hosed up something when they did the expansion - usually you know about that right away! Or - someone didn't update the VM directory to indicate the disk is now owned by this guest.. rarer but I've seen it happen. Other than the virtual nature of the disks and that they aren't hardwired to the server, I don't see any reason to handle them differently than in the x86 world. They're no more dangerous on z/VM than they are anywhere else.. Any of the reasons an LVM might 'go bad' on x86 applies to z/VM as well (and vice-a-versa).. Admittedly - it's probably easier to yank a disk away from a guest than it is to yank a hard drive out of an x86 server :-) Scott Rohling On Thu, Aug 14, 2008 at 10:13 AM, Ryan McCain <[EMAIL PROTECTED]>wrote: > > My point of view is that there is only one reason to put / in an LVM: > > easier expansion if needed. Some of those calls others have referred to > in > > the middle of the night can happen because root fills up.. and being > able > > to dynamically add space without bringing down Linux can be an easy fix > > until the cause of the unexpected file writing can be determined. > > That is how I'm looking at it. Saying that, I'm not very familiar with the > inner workings of z/VM. > > All of our 100+ x86 Linux servers have / in LVM and over the past year > we've had to completley rebuild a server maybe once. I guess I don't > expect the 3am calls like everyone else because I've never had them before > w/ Linux on x86. > > >>> On Thu, Aug 14, 2008 at 11:01 AM, in message > <[EMAIL PROTECTED]>, Scott > Rohling > <[EMAIL PROTECTED]> wrote: > <> [EMAIL PROTECTED]> wrote: > > > >> Is there a list of pro's and con's somewhere? > >> > > > > There may be some list out on the web - but to me there are just a few: > > > > Pro: > > > > - Extending root can be done without restarting the guest, by adding a > > volume to the VG and doing an ext2online. Same reason for putting > app/data > > into an LVM.. > > > > Con: > > > > - Recovery can be trickier if you're used to only have a single root > > partition. > > > > There also seems to be a faction which contends that if you separate your > > 'growing' directories (/usr, /var, /tmp, etc) then root should not grow > or > > need to be extended. Make those directories LVM's and mount them over > the > > appropriate dir. > > This can work well and can be done whether you use an LVM for root or > not. > > > > My point of view is that there is only one reason to put / in an LVM: > > easier expansion if needed. Some of those calls others have referred to > in > > the middle of the night can happen because root fills up.. and being > able > > to dynamically add space without bringing down Linux can be an easy fix > > until the cause of the unexpected file writing can be determined. > > > > Scott Rohling > > > > ---------------------------------------------------------------------- > > For LINUX-390 subscribe / signoff / archive access instructions, > > send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or > > visit > > http://www.marist.edu/htbin/wlvindex?LINUX-390 > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or > visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
