I had a server admin install a new drive in RAID 1 (mirrored drives). I'm not the best linux guy in the world... but is there a way either through linux, WHM/cPanel, etc. to check and verify that the drives are mirroring correctly? I just want to sleep soundly everynight knowing if a drive failed I'd have another drive up and going.
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.
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.
[url]
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 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?
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.
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?
We had a non-client (not on our server) that was getting 550 email rejections when he attempted to email us due to having Sender Verify enabled.
In the past I figured Sender Verify was necessary for fighting spam, amongst other things, but have realized that we may be having more rejections than we know because we never hear about them.
Is there a general best practice in terms of enabling Sender Verify or leaving it off? I've never heard about complaints about rejects from legitimate emails senders, so it doesn't seem to be an issue, but then again, you really never know...
!verify = helo !verify = reverse_host_lookup in exim acl and drop message if helo is not passed. But one issue is this validates for users even having account in the server and trying to send mail using server account to someone else
I want to put validation for only incoming mails "to" this server
What i dont want is to validate the mails that authenticated smtp users send
if there was a way of remotely verifying my dedicated server architecture.
The hosting is done through our design company who then use a 3rd party for hosting a number of sites, and as such I don't have direct access to server control panels etc.
Short of just taking their word for the fact that we have the servers we're supposed to, I was wondering if there's any way I can be sure. We're supposed to have dual web servers plus a database server.
in the last couple of days we really have problem accessing web service, while ftp, ssh, work fine. While we getting connection time out, the load on the server is really load around .2 and get numerous e-mail from Cpanel that httpd is failling and try to restart.
How can i do to check and verify that there a DDOS attack?
What step can i do to possibly minimize DDOS attack?
I recently purchased a new Dedi server, and got 100 MBPS Uplink. Now, I'm uploading 16GB size of files into this server, and I have a suspicious feeling that this upload speed is not what they told me. For the very 1st day, I opened a ticket and they said that they upgraded it to 100 mbps. I saw this speed was faster immediately. On 2nd day, it went down to around same slow speed before. Since then, I kept opening a new ticket and they said it was done, or sometimes I am under DDos attack..? What? I don't even have the site up yet! How come there is DDos attack?
Anyway, today I was told that I'm getting billed for this 100 mbps uplink, because it's a new service. What a crazy thing going on here... I am so tired of this ticket game and just don't understand why they don't commit what they told me initially.
Can anyone please tell me how I can verify and prove that I am having this 100 MBPS Uplink speed? The only thing I can tell with my eyes is that I can see those FTP upload progress bar. When it's very fast to upload one file, I assume that I have right speed.
But is there any tool or command that I can execute on the server shell, and tell them what I get as a proof?
If you enable ssl in apache, you can verify a client certificate. If so apache will create a environment variable for you with the name 'SSL_CLIENT_VERIFY' with values 'NONE, SUCCESS, GENEROUS or FAILED:reason'. URL....What is the meaning of this different values?
We are facing an issue i.e "Can't verify server identity",When we hit the platform 'teampark.sogeti.com' from android mobile application.Whenever we hit teampark.sogeti.com from Mobile Application ( IBM connections android App), our initial request will hit our Reverse Proxy and Validates the user certificate and forward it to the next level.We are using Apache 2.2.9 as our Reverse Proxy.
I have this customer who have been having trouble to receive some emails from valid senders due to Sender verify failed, both senders have valid accounts.
Here is an example,
De: MDaemon at zeus.XServer.com [mailto:MDaemon@zeus.XServer.com] Enviado el: sábado, 17 de noviembre de 2007 11:16 a.m. Para: albertocarbone@XServer.com Asunto: Error permanente de entrega
Failed address: jsoler@CustomerDomain.com
--- Session Transcript --- Sat 2007-11-17 11:15:19: Parsing message [xxxxxxxxxxxxxxxxxxxxxxxxpd35000148823.msg] Sat 2007-11-17 11:15:19: * From: albertocarbone@XServer.com Sat 2007-11-17 11:15:19: * To: jsoler@CustomerDomain.com Sat 2007-11-17 11:15:19: * Subject: RE: Zona Franca.- Concepto.- Sat 2007-11-17 11:15:19: * Message-ID: [003201c82934$ba953d00$2fbfb700$@com] Sat 2007-11-17 11:15:19: Intentando SMTP conexión con [CustomerDomain.com] Sat 2007-11-17 11:15:19: Resolviendo registros MX para [ CustomerDomain.com] (Servidor DNS: 200.118.2.66)... Sat 2007-11-17 11:15:23: * P=000 S=000 D=CustomerDomain.com TTL=(240) MX=[ CustomerDomain.com] {xx.xxx.13.172} Sat 2007-11-17 11:15:23: Intentando SMTP conexión con [xx.xxx.13.172:25] Sat 2007-11-17 11:15:23: Esperando la conexión del socket... Sat 2007-11-17 11:15:23: * Conexión establecida (xx.yyy.51.30:3948 -] xx.xxx.13.172:25) Sat 2007-11-17 11:15:23: Esperando la iniciación del protocolo... Sat 2007-11-17 11:15:25: [-- 220-svr01.customerDomainHost.com ESMTP Exim 4.68 #1 Sat, 17 Nov 2007 11:15:29 -0500 Sat 2007-11-17 11:15:25: [-- 220-We do not authorize the use of this system to transport unsolicited, Sat 2007-11-17 11:15:25: [-- 220 and/or bulk e-mail. Sat 2007-11-17 11:15:25: --] EHLO zeus.XServer.com Sat 2007-11-17 11:15:25: [-- 250-svr01.customerDomainHost.com Hello zeus.XServer.com [xx.yyy.51.30] Sat 2007-11-17 11:15:25: [-- 250-SIZE 52428800 Sat 2007-11-17 11:15:25: [-- 250-PIPELINING Sat 2007-11-17 11:15:25: [-- 250-AUTH PLAIN LOGIN Sat 2007-11-17 11:15:25: [-- 250-STARTTLS Sat 2007-11-17 11:15:25: [-- 250 HELP Sat 2007-11-17 11:15:25: --] STARTTLS Sat 2007-11-17 11:15:26: [-- 220 TLS go ahead Sat 2007-11-17 11:15:26: SSL negotiation successful (TLS 1.0, 1024 bit key exchange, 128 bit RC4 encryption) Sat 2007-11-17 11:15:26: --] EHLO zeus.XServer.com Sat 2007-11-17 11:15:26: [-- 250-svr01.customerDomainHost.com Hello zeus.XServer.com [xx.yyy.51.30] Sat 2007-11-17 11:15:26: [-- 250-SIZE 52428800 Sat 2007-11-17 11:15:26: [-- 250-PIPELINING Sat 2007-11-17 11:15:26: [-- 250-AUTH PLAIN LOGIN Sat 2007-11-17 11:15:26: [-- 250 HELP Sat 2007-11-17 11:15:26: --] MAIL From:[ albertocarbone@XServer.com [mailto:albertocarbone@XServer.com] ] SIZE=23231 Sat 2007-11-17 11:15:26: [-- 250 OK Sat 2007-11-17 11:15:26: --] RCPT To:[jsoler@CustomerDomain.com] Sat 2007-11-17 11:15:30: [-- 550-Verification failed for [albertocarbone@XServer.com] Sat 2007-11-17 11:15:30: [-- 550-Called: 82.165.181.92 Sat 2007-11-17 11:15:30: [-- 550-Sent: RCPT TO:[albertocarbone@XServer.com] Sat 2007-11-17 11:15:30: [-- 550-Response: 550 Backscatter Protection detected an invalid or expired email address Sat 2007-11-17 11:15:30: [-- 550 Sender verify failed Sat 2007-11-17 11:15:30: --] QUIT --- End Transcript ---