I've been using it a bit at home and I've always bashed software raid, but gota say its quite impressive and very manageable. I could see it become super easy to deploy cheap raid without paying extra for a raid controller, with the right custom software.
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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.
We are currently looking for Monthly Leased Virtuozzo Licenses, does anyone know who offers this? SwSoft only sells owned licenses which we don't need.
View 5 Replies View RelatedSo 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
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.
[url]
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'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?
I am putting together a 1u Linux server. It's for VPS's.
I intend to use s/w RAID 1 with 2x 500mb harddrives. I am wondering if I am better off buying two different makes of disks, to mitigate the risk of bad batch of disks. Is there any disadvantage to this, i.e. is there a good reason to keep the disks identical?
O/S will be Centos 5 x64
I know on windows, you just add a new HDD, right click and select drive mirror, on an already fully operational box.
On Linux I know you can setup software raid during the initial installation.
Is there any way to add mirriroing of any kind on an already installed system?
at implementing RAID 5 into my RHEL4 box, and am wondering what the best configuration would be. I'm not very familiar with LVM, but I've heard great things about it.
View 3 Replies View RelatedI've just bought myself a linux based NAS for storage/backups at home and a couple of WD Greenpower (Non-RAID edition) HDDs.
For those who don't know what TLER is (Time Limited Error Recovery), without it enabled the HDD does its own error recovery, which may take longer than the acceptable time for a RAID Controller. In which case, the drive is kicked out of the array. With TLER on, the idea is that the drive keeps notifying the controller, or the controller handles the error.
So, my actual question is, does Linux Software RAID benefit from TLER being enabled? Or is it best to let the drive do it's own thing?
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.
[url]
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 have bought an Intel SR2500LX server chassis with a S5000PAL mainboard running Centos. This system has an active backplane with a LSI MegaRaid chipset.
I'd like to be notified in the case of a drive failure but I'm totally stumped on how to get any monitoring working.
The only raid managment utility Intel supplies is a Java based monstrosity, which needs X-Windows to run and needs to be run continuously in order for the email notification to work.
Web based management can only be used from the same subnet as the server, so that's not very useful either.
I've contacted Intel support which gave me the advice to reboot the server and use the Bios utility if I want to check the Raid arrays consistency . Needless to say I'm very dissapointed, this server has every redundancy feature you can think of but it seems impossible to monitor the Raid under Linux.
Does anybody have experience with the Chassis and Raid monitoring under Linux?
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.
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 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 ?
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 was building a 1u server a month or so ago to colocate. After screwing up the purchase of the raid card (got a pci 64 or something) its been sitting next to me not doing much. I need to go ahead and find a good raid card and get this colocated,
I have literally spent hours on Newegg, Amazon and Ebay and found nothing that really jumps out at me. When people were helping with the build before, Adaptec was recommended, but the card is now deactivated on newegg so I am looking again.
put together a high availability cluster for a PHP + MySQL based app to run on a LAN. We're going to use Linux, and cost is a major consern. The app itself doesn't use / need too much resources, as it will only be accessed by 2 / 3 people at a time, so I'm using the following:
2 identical PC's with:
3Ghz PIV CPU
1GB RAM
2x SATAII 160GB HDD space setup as RAID 1
10/100 Mbps LAN NIC's, on a 100MB 8 port switch
Up to now I have been running MySQL-Max 5.0.15 to run a MySQL master-master replication server, which works fine, but the setup involved a lot of manual work, and downloading of the right binaries.
Furthermore I used Linux Heartbeat todo auto switchover between the two servers & RSYNC to sync the application files between the two. This has been working fine untill one of the server's HDD's failed recently corrupting both HDD's
So, I need a better way of doing this, and want to meet the following requirements:
If 1 HDD fails on either server, the server still needs to be able to run without a problem.
Replacing a HDD & rebuilding the RAID array should be easy to manage, preferabbly over the net.
Setting up a cluster should be easy to manage, both for the MySQL DB server & the files that need to be synced between the two machines Re-installing the server should be easy todo as well.
For No.1 I have been thinking of setting up RAID 5 with 4x HDD's - how reliable / safe / redundant is this?
For No. 4 I have been thinking of using something like sysimager to backup the server once setup, but will / can it recreate the RAID array upon restoration? The MySQL DB & PHP files are being backed up to a removable HDD on a daily basis.
The client is 700Km's away, so we can't just drop-in to fix things as often as we like. Thus redundancy is of utter importance. Currently I'm running Suse 9.3, simply due to the fact that it's easy enough to tell the client over the phone howto do things with YaST. Suse 10.1 will be used for the new setup, but I could also use Fedora Core 5, and have also been thinking of using SME server 7.0.
I'm about to purchase a new Xeon dedicated server, however I'm unsure whether to opt for a RAID 1 configuration on the two 320GB SATA drives. Can this decrease performance in anyway or only increase? I run an extremely resource hungry site utilising audio/video en/decoding, running vBulletin so anything that might negatively affect performance could have a big impact.
Secondly, I'm unsure on whether to opt for CentOS 5 over 4.5. I'll be using cPanel of which I've heard there have been problems with the latest release of CentOS.
And finally, is it worth upgrading to Apache 2 and MySQL 5 (which I know is installed as default on CentOS 5)? The reason I ask is that I've heard of server load problems after upgrading to these latest versions on high traffic sites.
I`m building some Xeon Nehalem servers for shared hosting with cPanel. The servers will be:
Dell PowerEdge R410
Xeon Nehalem E5502
12GB DDR3 RAM
3ware raid controller
But for shared hosting, is it worthy to have a RAID-10, or would a RAID-1 be enough?
We have some Xeon E3xxx servers running with RAID-1 hosting more than 1000 accounts, we hadn`t had any IO/load problem so far.
I have a delicated server with "Intel RAID Controller: Intel(R) 82801ER SATA RAID Controller",I cannot find information on this raid.The 80 GB harddisk is about 4 years old,if one harddisk fail,I wonder if I can swap a new one bigger capacity and it will auto rebuilt?
View 2 Replies View RelatedI haven't yet broken into the realms of dedicateds, although I have a decent VPS and am anticipating the need to get a dedi in the future.
Hence I'm wondering briefly why exactly RAID (insert some random number?) is recommended? I know it does something to do preventing hard drive failure, although would an efficient backup system be a decent alternative with regards to cost?
When you order a dedicated server, do you opt in for the hardware raid? Why or why not?
View 14 Replies View RelatedI'm running a busy web hosting server with about 300 domains with no raid mirroring. I just installed a new HD in it.
Is it possible to make a raid1 via software?
I have several servers that have a HighPoint RocketRaid 1520 SATA raid card. I have recently discovered that this card requires drivers in the OS to actually take advantage of the raid functionality.
Well, it seems the drivers were never installed. So I essentially do not currently have a raid setup, even though I have a pair of HD's in each of the servers affected. Now, I do have a Windows server that automatically loaded the driver, but the Linux boxes do not have the driver it seems. The instructions for this card state that the driver is installed at the time of OS installation. I bought these servers when I acquired a host a couple of years ago and obviously they weren't setup properly.
So here's my question, I am thinking of trying to install this raid driver on the affected servers now. They have been running for a couple of years this way and I don't want to screw something up. Is this something that I can do at this point without going back to reinstalling the OS, etc? Can the raid driver be installed after the fact here like I'm thinking of doing?
Should I proceed with trying to get this RocketRaid card to work or would I better off buying hardware raid cards that are configured outside of the OS? And if I should go with the hardware level raid, what card do you all recommend? I'm running RHE3 on these servers and they are P4's with 1GB of RAM.
