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-   -   About LVM, is this hosting company honest ? (http://www.linuxquestions.org/questions/linux-server-73/about-lvm-is-this-hosting-company-honest-614222/)

yuye811 01-17-2008 04:55 AM

About LVM, is this hosting company honest ?
 
I am current paying for a dedicated server in Canada.
do a "df -h" after login:

------------------------------------size-Usd-Ava------
/dev/mapper/volumeGroup123-LogVo123 200G 10G 190G ...
/dev/sda1 100M 10M 90M ... /boot
tmpfs 100M 0 100M ... /shm

So this means the 200G is on LVM -- Logic Volume, well, my question is that is this company actually honest with me ?

If this is a dedicate server, why would they use LVM ?
It seems to me, the server has very small local hard drive, then share Logical Volumes through the network with many other servers. This allows them to keep the Shared Hard Drives as few as possible and add more only if all the clients are using up more space.

the amount of Space they need to keep up is :

= hd space used by all clients + hd space offered to an individual client (200G) in this case


Am I paranoid or do you also agree with me?
I am not revealing hosting company name, and exact numbers, because I am not at "expert level" with linux and don't want to draw wrong conclusion.

yuye811 01-17-2008 05:01 AM

I am doing df because today, first I got seesion effort, telling me that "read only system blah blah" , so I root ssh in, and try to restart httpd, I can't restart :

Starting httpd: (30)Read-only file system

well, so I starting to think there might be problems with filesystem.

df to find out it is mapped hard drive

I don't much experience with LVM, do people complain about LVM's stability ? (guessing it is related to stability)

billymayday 01-17-2008 05:12 AM

I don't follow your logic

Set up a server under RedHat for example, and you get a similar df, since RH uses LVM by default. LVM just lets you combine multiple drives into a single logical volume that appears as one in the file system.

Since your /boot is sda1, I'd expect this to be a single machine

rupertwh 01-17-2008 05:14 AM

I'd say yes, you are paranoid. ;o)

Have a look at the LVM Howto and do a
Code:

fdisk -l
to see what physical hard disks your machine has.

yuye811 01-17-2008 05:19 AM

CentOS 5
500 GB SATA

Site offers two plans:
plan A tell you explicitly that "two" 500G
Which implicitly suggest that plan B is single 500G

yuye811 01-17-2008 05:27 AM

# fdisk -l
gives:
-bash: /sbin/fdisk: input/output error

# ps
gives:
-bash: /sbin/ps: input/output error

Basically only few commands work now, "reboot" is not working either.
I think I am planning to just pay a bit more to get colo in LA. So frustrating almost every other day, I run into problem that php session is read-only.

i am going to try fdisk -l when server is back.
if the hard drive is mounted through network, what am I supposed to see when fdisk -l ?

syg00 01-17-2008 06:30 AM

a) yep, you're paranoid
b) you've got a filesystem problem. That needs to be fsck'd, and you may not be able to do it.

How good are your backups ???.

yuye811 01-18-2008 12:40 AM

a) I wasn't sure, so I tried not to accuse host company
b) no, I have no backup
yes, I can run "fsck", (I notice on VPS it doesn't allow fsck) it gives me following message:

WARNING!!! Running e2fsck on a mounted filesystem may cause
SEVERE filesystem damage.
Do you really want to continue (y/n)?

I am a developer in real life, never bothered with backup operation, so what do you recommend ?
Making a small sports hobbit website. will have a database, and some images files, later might have some videos(not soon).

billymayday 01-18-2008 12:42 AM

Perhaps try fsck -N to see if there's anything wrong in the first instance

trickykid 01-18-2008 08:13 AM

You probably do have a dedicated server but as a Virtual Server with 10 other clients. That's how a lot of hosting providers work and can provide dedicated hosting to many customers. I seriously doubt they have a 5-10k dollar server they're providing for the average prices along with all the other costs in a hosting type environment.

They market a dedicated server and that's what you got most likely, just remember though they might have 10-15 dedicated servers on one server though.. which is legal and okay really. ;)

And I've dealt with read only filesystems with dedicated hosting providers, unless you have some other remote access or physical access, you'll need to contact support in most cases. Call support, tell them issue, they'll have it fixed in a few minutes most likely if they have decent support.

KnightHawk 01-18-2008 02:36 PM

Quote:

Originally Posted by trickykid (Post 3027090)
You probably do have a dedicated server but as a Virtual Server with 10 other clients. That's how a lot of hosting providers work and can provide dedicated hosting to many customers. I seriously doubt they have a 5-10k dollar server they're providing for the average prices along with all the other costs in a hosting type environment.

They market a dedicated server and that's what you got most likely, just remember though they might have 10-15 dedicated servers on one server though.. which is legal and okay really. ;)

And I've dealt with read only filesystems with dedicated hosting providers, unless you have some other remote access or physical access, you'll need to contact support in most cases. Call support, tell them issue, they'll have it fixed in a few minutes most likely if they have decent support.

And I'd add to this, that doing things like fdisk, starting and stopping services, and mucking around with php sessions are exactly the sort of things that a good admin on a shared system will not let you do.

trickykid 01-18-2008 03:46 PM

Quote:

Originally Posted by KnightHawk (Post 3027420)
And I'd add to this, that doing things like fdisk, starting and stopping services, and mucking around with php sessions are exactly the sort of things that a good admin on a shared system will not let you do.

Well not really in this situation. He probably is root for the OS instance and Virtual Machine they have dedicated for him. What's impossible usually is if the system is read-only due to actual hardware issues (I've seen controllers cause this issue on a hardware level) and with a read only filesystem where nothing can get written to it, reboot won't work. Nothing will essentially work. Who knows if the Virtual Machine is on a filesystem on the server that only has read only access.

That's why at this time, they need to call their support and explain the situation. I'm willing to bet it'll be fixed in a matter of minutes, most likely after a cold reboot of the system.

yuye811 01-18-2008 11:09 PM

Sorry for the confusion.
My problem was encountered on that dedicated server, not VPS.
I do have a VPS at godaddy. And I know I can't use fdisk.

I couldn't do fdisk, ps on the fully dedicated server (tell me input / out error). Not a Virtual Machine. I contacted the support to reboot. After reboot, ps and fdisk allowed again.

trickykid 01-19-2008 09:01 AM

Quote:

Originally Posted by yuye811 (Post 3027776)
I couldn't do fdisk, ps on the fully dedicated server (tell me input / out error). Not a Virtual Machine. I contacted the support to reboot. After reboot, ps and fdisk allowed again.

That's the only way to get around the read-only in most cases, reboot like I explained earlier. But really, don't let them fool you, it's most likely a dedicated server but as a virtual server. Like explained before, I don't know how much you pay per month but if it's probably $200 or less a month, you got yourself a virtual dedicated server. ;)

yuye811 01-19-2008 04:52 PM

I emailed them, they told me it is not VPS.

The key point of the problem is that I don't want to see the Server run into "session read-only" problem every other day. Most of the time I can run Reboot command and take care of it. But rebooting every other day is just crazy to think about. Their support never ever answers the phone, only way to get them is via email and wait.

I am going to cancel the hosting, I already ordered a server from tigerdirect. Once the hardware arrive, I am going Colo in LA downtown where I can have physical access to.

Thank you guys for providing answers and opinions ~ Have a nice weekend ~


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