RAID 1 Or HDD Mirroring
Apr 2, 2008I am looking for Backup Utility . Came across this two terms
Are RAID 1 & HDD mirroring synonyms?
Which is better RAID 1 & HDD mirroring?
I am looking for Backup Utility . Came across this two terms
Are RAID 1 & HDD mirroring synonyms?
Which is better RAID 1 & HDD mirroring?
I was wondering if anyone knows of any provider that provides RAID VPS Mirrored Hosting.
So if one drive goes down, the site will immediately switch over to the next one in the cluster.
Quote:
Today we are going to conduct a detailed study of RAIDability of contemporary 400GB hard drives on a new level. We will take two "professional" drives from Seagate and Western Digital and four ordinary "desktop" drives for our investigation. The detailed performance analysis and some useful hints on building RAID arrays are in our new detailed article.
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Is Motherboard RAID as good as a dedicated PCI-E card? I am guessing a dedicated card is the best option, though costs more.
We are looking at buying a barebones server from Supermicro. It features an onboard RAID controller which supports RAID 0, 1, 5 & 10 - but for some strange reason it will only support RAID 5 if you use Windows. Here is a link to the page detailing the RAID features.
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We are going to be running Linux, CentOS 5.1, so we will only have the choice of RAID 0, 1 or 10. This isn't an issue, as having RAID 10 on 4x SAS (15k) drives will be fine for speed and stability. What is an issue is would this RAID controller be as fast or reliable compared to a dedicated PCI-E card? If it can only use RAID 5 in windows, does that suggest this controller is too reliant on software? It would be a nightmare to suffer downtime and data loss because the controller couldn't hack it during a drive failure, or one day it decided to bugger up the array when rebooting.
So that leads me to looking at this card, this looks very good for what we need. Are adaptec a reliable brand? I've seen it advertised for £200, which is a good price.
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This card features RAID 5 and 6, would RAID 6 be better than RAID 10 for redundancy, or is it too slow to bother with? Also it seems to have a battery module available for it, what does this achieve? Cos surely if the power dies the hard drives and motherboard can't run off this little battery, or does it just help the controller stay alive long enough with some hard drive information in its memory if the power goes out during a rebuild?
I could try the Software-RAID 5 of the EQ9 Server of Hetzner.
Does anyone here has experiences, how fast a hardware raid 5 compared against the software-Raid 5 is?
The i7-975 should have enough power to compute the redundnacy on the fly, so there would be a minimal impact on performance. But I have no idea.
I want to run the server under ubuntu 8.04 LTS x64.
On it a vitualisation like VMware the IO-Load could get really high.
So I've just got a server with 2xSATA raid 1 (OS, cpanel and everything in here) and 4xSCSI raid 10 (clean).
Which one do you guys think will give the best performance:
1. Move mysql only to 4xSCSI raid 10
2. Move mysql and home folder to 4xSCSI raid 10
I am in a somewhat complicated situation... I wanted to order a custom server with hardware 3Ware RAID controller but after over a month of waiting I was told the HW RAID controller, as well as any other 3Ware controller they tried, does not work with the motherboard used in the server from Fujitsu-Siemens and that they simply got a reply from FS that the controller is not certified to work with their motherboard.
So although I'd prefer a HW raid, I am forced to either choose a different webhost or setup a software RAID. The problem is, I haven't done that before and am somewhat moderately...scared
I have read a lot of the info about SW RAID on Linux that I could find through Google but there are some questions unanswered still. So I thought that perhaps some of the more knowledgeable WHT members could help me with this problem...
The server specs will be:
Core2Duo E6600 (2.4Ghz), 2GB RAM, 6-8x* 250GB SATA II HDDs, CentOS 4.4 or SuSe, DirectAdmin
* I prefer 8 HDDs (or actually 9) over 6 but I am not sure if their server chassis can hold that many HDDs, I am awaiting answer from them. They don't have any other drives beside the 250GB ones so I am limited to those.
The preferred SW RAID setup is to have everything in RAID 10, except for the /boot partition which has to be on RAID-1 or no RAID I believe, plus one drive as hot spare (that would be the 9th drive). I am quite sure they will not do the setup for me but will give me access to KVM over IP and a Linux image preinstalled on the first HDD so that I'll have a functional system that needs to be upgraded to RAID-10.
How do I do that? The big problem I see is that LILO or GRUB can't boot from a software RAID-5/10 so I will have to mount the /boot partition elsewhere. It's probably terribly simple...if you have done it before which I have not. I have read some articles on how to setup a RAID-5/10 with mdadm (e.g. [url] ) but they usually do not talk about how to setup the boot partition. Should it be setup as a small sized (100-200MB) RAID-1 partition spread over all of the drives in the otherwise RAID-10 array?
What about swap? Should I create a 4-8GB (I plan to upgrade the server RAM to 4GB in near future) RAID-1 swap partition on each of the disks or swap to a file on the main RAID-10 partitions. The second sounds simpler but what about performance? Is swapping to a file on RAID-10 array a bad idea, performance wise?
Is it possible to grow a RAID-10 array in a way similar to growing a RAID-5 array with mdadm (using two extra drives instead of one of course)? mdadm doesn't actually even mention RAID-10 despite it does support it without having to create RAID-0 on top of RAID-1 pairs if the support is in kernel, from what I know.
How often do RAID arrays break? Is it worth having RAID if a servers hard drive goes down? I was thinking it may just be a better option to just have a backup drive mounted to my system and in the even of a system failure just pop in a new hard drive, reload the OS, and then reload all my backups?
View 14 Replies View RelatedI have a new server and it is rather slow during raid 1 recovery after system installed
CPU: Intel Core2Duo E5200 Dual Core, 2.5Ghz, 2MB Cache, 800Mhz FSB
Memory: 4GB DDR RAM
Hard Disk 1: 500GB SATA-2 16MB Cache
Hard Disk 2: 500GB SATA-2 16MB Cache
root@server [~]# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sdb1[1] sda1[0]
256896 blocks [2/2] [UU]
md1 : active raid1 sdb2[1] sda2[0]
2096384 blocks [2/2] [UU]
md2 : active raid1 sdb4[2] sda4[0]
480608448 blocks [2/1] [U_]
[=======>.............] recovery = 36.7% (176477376/480608448) finish=1437.6min speed=3445K/sec
the sync speed is just 3.4Mb/second and the total hours needs to be more than 40 hours
Also the server load is very high (nobody uses it)
root@server [~]# top
top - 07:00:14 up 16:55, 1 user, load average: 1.88, 1.41, 1.34
Tasks: 120 total, 1 running, 119 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.0%us, 0.2%sy, 0.0%ni, 99.7%id, 0.0%wa, 0.0%hi, 0.2%si, 0.0%st
Mem: 4148632k total, 747768k used, 3400864k free, 17508k buffers
Swap: 5421928k total, 0k used, 5421928k free, 569252k cached
I am in the process of restructuring the infrastructure on our servers. I am thinking of using either RAID 5 (1 hot spare) vs RAID 10 as my 1U server has 4 HDD tray.
RAID 5 would have better capacity but RAID 10 has better overall performance. Which one do you guys go for a shared hosting server?
Is it possible to turn a non raided setup into Linux software raid, while it is live, and if it's the OS drive? Can you even software raid the OS drive remotely? I've been thinking about doing it for the redundancy (and possible slight performance boost for reads, but doing it more for redundancy). I'm using CentOS.
View 12 Replies View RelatedI want to take some data from a raid-disk (taken from a raid-1 sstem). Put it into a new system already, but this system doesn't have any raid.
When viewing "fdisk -l", it said /dev/sdb doesn't contain valid partition. Is there anyway I can mount it now? I am on CentOS 4 box
MY server configure our drives with RAID-1.
How can I check it my server configure with 3ware or software raid ?
Also please advise me how can I monitor raid configuration that my raid is working fine or no ?
I've been talking to the Planet about trading in my four and a half year old "SuperCeleron" (from the old ServerMatrix days) Celeron 2.4 GHz system for something new. As part of their current promotions, I've configured a system that looks decent:
Xeon 3040, 1 gig of RAM, 2x250GB hard disks, RHEL 5, cPanel+Fantastico, and 10 ips for $162.
Not too bad. I could bump up the ram to 2 gb for, I think, $12 more, which I'm thinking about and wouldn't mind some thoughts on. But, the thing that has me really confused is RAID. I like the idea of doing a RAID 1 setup with those two hard disks. But, the Planet wants $40/month for a RAID controller to do it. I really don't want to go over $200 a month!
Any thoughts on alternative redundancy strategies that might avoid that cost? Software RAID does not seem to be offered by the Planet, unless I can figure out how to do it after installation (is that possible?) Better ideas in general on the server?
Just curious what your thoughts are on performance:
2 SCSI Drives 10k w/RAID 1
or
4 SATA 10k w/RAID 10
Prices are not too different with 4 drives just being a tad more.
how well software raid can perform and how it compares to hardware raid. How does software raid actually work and is it worth it?
How should I look at be setting up software raid if I was going to? Would you recommend just to use hardware raid instead?
Which do you guys recommend of the following?
4x 73GB 15,000rpm SAS drives in a RAID 10
or
4x 73GB 15,000rpm SAS drives in a RAID 5 w/ online backup
I have a VPS-A with company A, within, I have 30 accounts.
Now, I wish to split them with min-impact, ie VPS-A with company A and VPS-B with company B (looking for 1 if you can suggest 1 good VPS company) where VPS-B will host also all the accounts in VPS-A.
Then, I wish to be able to have VPS- B mirror to VPS-A and so, if VPS-A is down, my 100 clients in VPS-A will not be affected and automatically swing to VPS-B.
What is my investment and what should I do to acheive that?
Alternatively, I hope, dreamfully, that VPS-A and VPS-B will be both active and VPS-A are VPS-B mirror and vice-versa.
In VPS-A, I have client 1 - 50 active and client 51- 100 mirror from VPS-B and in VPS-B, I have client 51 - 100 active and client 1 - 50 mirror from VPS-A.
In anything, I can balance the load from both VPSs and if one of the VPS is down, I can swing to the other and still with min-impact.
Then, when my faulty VPS is up, how can I swing back the 50 client to the original VPS?
I hope that my client do not need to change their dns if there is a downtime and also, auto update both VPS if there is an content or email uipdate from my client.
In Short,
1. I'm looking for another good VPS
2. How do I achieve mirroring with auto update to 2nd VPS without having my client changing their DNS when my VPS is down.
3. How do I achieve mirroring and load-balancing between 2 VPS without having my ciient changing their DNS when one of it is down and how to restore back when VPS is up again.
I run a small company and we have a web based application accessed by our customers, this application lets our customers run their business, tracking working, producing parts orders, job cards, invoicing etc.
The database we use is SQL 2005, what we are trying to achieve is have another server, either alongside the existing one, or if it would work at another location where the data from one server is written to the other server, so in the event one server went down we could quickly switch to the second server, my questions -
1, Is this possible?
2, If it is what impact does it have on the performance of server one?
3, Do both servers have to be in the same location?
4, How easy is it to configure assuming its possible.
5, Is there anything else I should be aware of?
my setup to start:
I've got two servers is two different locations.
one of them, the master server ( we'll call server A ), runs a large web site with a lot of content and a mysql server.
I've setup another server ( we'll call server B ), that is completely in sync with server A, both mysql and all data using mysql replication and rsync for data.
also I've setup round robin dns, which is also working correctly.
Now, my question is:
if server A goes down, and server B picks up after it.
how can i get those changes that were made on server B back in sync with server A when it comes back up. example, a use uploads files, or posts/edits/deletes data from mysql.
how should i handle this?
any ideas would be great, I'm sort on stuck on this one for the moment.
We are considering buying rackspace at a datacenter, and setting up two servers. The first would be the primary, lets call it Stewie. The second is called Peter.
Is it possible to setup some sort of either software or hardware solution that automatically mirrors all data from Stewie to Peter automatically?
Basically we want a redundant setup, where if either one of the server fails, the other can take over without any interruption and loss of data.
I was wondering how I can mirror another server, I have a client website and they want redundant DNS so if one of their servers goes offline, the other will keep it up. Any ideas how I can set this up? Is it difficult to do?
View 7 Replies View RelatedWe have a webportal that has a lot of data... and we have different versions of this portal in different languages (russian, italian, chinese).
Now for better performance in china we took a web hosting there and made a copy of the portal there...
It is working as expected but it is really hard to mantain different versions of portals on different servers with separated databases and all other important scripts...
Now we are making a rewrite of our system and this rewrite will use a central database and unified data (so a user of the local (eg chinese) portal will be a user of the global portal too!
Now the portal is based on cakePHP and mySQL... so the business logic scripts and the database are only one for all the portal versions. The only thing that changes for each portal are the config files (one per portal).
Now, making it work on one server is easy but we would like to make mirror servers in russia, china and italy. Lets call them B, C and D and the main server: A.
Obviously all the servers should be in synchronisation between themselves. I've read mySQL has a replication function that would deal with the DB synch. What about other files? The portal allows users to upload their photos, avatars, attach documents and video content. We would like this files to be synchronised too...
B<=>A
C<=>A
D<=>A
and not B<=>C
or B<=>D
How do we achive this?
First of all appologies if this is posted in the wrong forum, was unsure of where to ask the following questions.
We have a web server running a web application accessed by a large number of users during a working day. On an evening the web server is set to back up the database to another web server at a different location.
The server is running SQL 2000 ( although we are just upgrading to SQL 2005)
My question is how easy would it be to setup our server so it "mirrors" to our back up server. What I mean by this is that at periods during a working day the database is transfered to our back up server at periodic intervals, say every 15 mins, so that in event we suffer a problem with our main server could re direct our users to our back up server, with little or no data loss?
If this is possible does it also put extra strain on our server that is being accessed, i.e. would users notice a slow down of server as data is moved about?
If all the above is possible, is there any easy way of pointing our domain name at the back up server within say 15mins or so of main server failure? if our main server went down we could not redirect users form main server to back up, so is there any method of making this happen in event of failure of main server?
Does anybody know how I can mirror a websute using PHP?
I have 2 dif domains on different servers different OS, and I need PHP to collect the page from the other server from another domain.
I'm building the infrastructure for a live event site.
I have specced 8 app servers but I'm still unsure with regards to MSSQL.
The site functionality makes a single write to the DB with no reads. A simple option would be to have a MSSQL DB instance on each of the APP servers and simply collate the information after the event.
I've also been looking at the mirroring function of 2005 as it would mean we could get away with two MSSQL servers instead of 8.
Has anyone used MSSQL 2005 Mirroring? Is it easy to setup and maintain? Any caveats?
I have two partitions on my server (C and D), looking to mirror both onto my second IDE drive for some fault tolerance.
Just wanted to know whether there are any real benefits in this.
Secondly, is it worth doing both the primary (c) and the data (d) partitions or having just the data partition and using the free space on the second drive for a backup solution (which would later send data to an off-site backup)?
I'm a web designer - not an IT guy, as such I'm not 100% on setting up servers/dev environments etc...
I'm freelance and currently working in-house for a client that has set up a dev server that supposedly mirrors their live site - its a catalogue site with loads of dynamic elements.
The dev site they've set up displays only the html, no images or stylesheets link up when i preview them in dreamweaver as they don't logically link to the page as the pages are templates drawn from various folders.
What I want to know is is it possible to mirror a dev server exactly like the live website so the scripts etc all work as they do on the live site. I'm pretty sure it is as I've worked on dev servers before but not one like this bloody mess. The IT bods here seem to think the dev server is the best that is achievable - are they right? am I missing something???
I can't really answer any technical questions apart from i think the dev server is an apache server - what do i need to explain to the IT bods to get my point across?
I want to prepare myself for getting dugg and whatnot, so I want to mirror my site ahead of tiem. The problem is that it's very db-intensive so there's a db that all mirrors would have to query. What's the best way to deal with multiple dedicated servers in order to spread traffic load and not crash my site?
View 3 Replies View RelatedWe’ve been asked to offer a technical proposal for a new established TV station, and the IT manager of the station has a long list of requirements, we covered it all, only one issues lift as we never done it before:
They want about 20-100 GB server for hosting and they want to have a mirror server, incase the 1st server was down, so it would redirect the visitors to the mirror server, I'm thinking of getting them a dedicated or semi-dedicated server, but how do you do the mirror issue.
Some one said to get two dedicated servers, but::
1. How we make it that when one is down, it automatically directed to the other, I believe there is software’s for that, so were do we install this software: the original server or the mirror server.
2. Should they be from two different companies and to different countries?
3. The web site will be with CMS and DB, how do you make sure that the mirror server have all the new data that was updated in the 1st server’s DB, do they have like shared DB or something, and how..
Any other information, links, or suggested hosting sites for reliable dedicated server (with big bandwidth) would be greatly appreciated.. thanx
P.S. We use PHP/ MySql technology.
Well I am looking to learn to manage a server (so I won't need to hire others to do what I can do). However I have some basic questions.
1) So lets say you have a server with two identical HDD's and raid 1?? or a SATA controller so that the second HDD is just a mirror of the first HDD when/if the first HDD dies does the SATA controller or RAID card see that the first HDD died and switch to the second HDD so the site that is hosted on the server stays online?? I am thinking yes as that would seem to be the point of having a raid or sata controller and setup ??
Part twoto the question is is their software that you need to install that will make the server email you when/if a HDD dies (so you can do pull the dead one out and replace it with a new one). Or is it just that you would watch some type of server log(s) to stay ontop of if the server is running all good??
Second is how common (these days) is it for a server that would be new and brand name have a HDD die or have some other hardware failure?