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7

First, stop and think about your realistic goals... The short answer to your question is that SAS is a switching protocol. The drives connected via expanders are all accessible and can be addressed transparently by a single controller. However, the rest of your questions are going to be a function of your particular controller, your storage architecture ...


5

Yes, this is where SAS expanders, enclosure backplanes and breakout cables come in. You can obtain a breakout cable that will provide 4 ports from the SFF-8087 mini-SAS connector. You can also try to use something like the HP SAS Expander to provide more SFF-8087 ports for your use from the single RAID controller. A detailed forum about the HP expander is ...


5

For Dell, "256MB Cache" means 256MB of battery-backed cache on the RAID card. This is the cache used by the card for I/O operations. It caches writes in this storage to re-order them for more efficient usage of your disk. The battery is there in case of power loss, the battery supplies voltage to the cache-RAM. I believe it lasts up to 2 days. "512MB NV ...


5

I got explanation from guys on VMWare forum in thread http://communities.vmware.com/message/2012333 . And the reason is that ESXi does no caching and completely relies on the controller for writing data to disks so speed 20MB/s with write-through cache mode (only mode this controller supports as it does not have BBU) is standard. Hyper-V is apparently doing ...


4

Stay away from the MegaCrap cards. LSI bought them for who-know-what-reason and should have put them out of their misery long ago. Get one of LSI's own SAS HBAs (assuming you want something good and from LSI, other manufacturers are out there too). There are "SFF-8087 to 4x SATA" cables around to plug such cards into 4 SATA drives. You can find them on ...


4

If I am reading the specs correctly then the LSI 9260-8I can support. up to 128 devices up to 64 logical drive support Is there even such a hard limit for a RAID controller? Yes, there is a limit on most controllers about the number of volumes that you will be allowed to create. But on any have decent controller, it is unlikely that you would ...


4

You were correct in understanding that the write cache solution would help performance. However, you just didn't order the right parts. What you ordered was a 512MB chip. The reason the flash capacitor is external to the memory module/RAID controller is to preserve the old form-factor of the older battery-backed module (forward-compatible). The part number ...


4

If you have two SFF-8087 ports on your controller, each one of those ports is a 4-lane SAS port. Natively, that would only be able to address EIGHT disks. With the use of an expander on the backplane, you can accommodate a greater number of disks. So if your backplane can fit TWELVE drives, there's an expander on it. Also, look at the server. See if there's ...


3

Yes, you just need to have the "receiving" RAID card import its configuration from the drives you're moving. It's not well known (at least to storage novices) but these cards not only store their configuration in their on-board NVRAM, but also in several places on each disk. The exact process varies from card to card, but it's typically a simple procedure. ...


2

Different RAID controllers? All bets are off. You may be able to get it to work with very closely-related cards of the same lineage, same firmware, etc., but it's highly unlikely that this is going to be supported by your hardware vendor. Honestly, this is where a well-implemented and well-tested backup regimen comes into play. You don't need to muck about ...


2

That certainly seems reasonable. Just make sure to verify your backup and do some test restores to make sure things are good to go there.


2

I have had a 9650SE-8i which broke. I called 3Ware and the lady who answered the phone informed me that the array configuration was stored on the drives and that plugging the old drives into a new (either identical or same line) card should just work. Since the local stores no longer carried 9650SE's I got a 9750. I am happy to report that things indeed ...


2

It should allow to rebuild onto a larger disk, how exactly did you try to initiate the rebuild? The proper way is to set the new disk as hotspare, and then a rebuild should start automatically


2

Because there's no cache coherency possible if you only leverage the caches of individual drives...


2

Well, from the log it all is ok, or? Rebuild started, no error, rebuzils still in progress.


2

Yes all of the Pxxx-series controllers will work just fine in a G5.


2

It's an HP server, so there should be some information about the hardware available in the vSphere client. I'm not clear if you're saying you have access to the client or not, based on your question. If you do have access, you can go to Configuration -> Health Status -> Storage to see the array setup. This only applies if you're using a version of ESXi with ...


2

20 users doesn't tell me much. 20 office clerks will handle data a lot differently than 20 video engineers. Same with databases. Storage can be tuned to a variety of purposes. If your goal is "lots of space, as cheap as possible without much downtime" that's one thing. If you have performance demands, that will impact the calculus. I lean against iSCSI for ...


2

No, you can destroy one array, add its disks to the other array, extend the logical drive, partition and OS drive then restore the extra data back on but the disk controllers don't care about the file system on their disks, just the arrays and logical disks presented to the BIOS. Oh and they do support dual R5 arrays, not a clever way of using that ...


2

The E200 is an entry-level controller. There are some limitations in its base configuration, so you should be mindful of those. The quickspecs for the controller are listed here: http://h18000.www1.hp.com/products/quickspecs/12460_na/12460_na.html Does your unit have a Battery-Backed Write Cache (BBWC) module? That is an necessary component if you wish to ...


2

The sarcastic bit of me wants to say "pop the case and read the label", but I'm making a real effort to be more helpful today... I'm a Linux bloke for the most part, so I'm not entirely sure, but the "MegaRAID Storage Manager - Windows" on this support page from LSI should be able to tell you the size of the RAID array components. Certainly the Linux ...


2

If you're unwilling to restart your system to install the manufacturer's tools you're basically going to sit here being stubborn until the machine completely dies. At that point it doesn't matter what you want. The machine will be down, probably for good. You won't have to worry about restarting because you'll have to do so as part of replacing the hard ...


1

No. GENERALLY not, and no with MegaRaid. There was once one that coudl do that (RaidCore IIRC) but that technology is not available anymore. As RAid cards function as independent sub-controllers you can not have a Raid volume spanning 2 of them. You can do that in the OS though.


1

Yes and no... Think about this: Your disks will not perform at 6Gbps (unless they're SSDs). So some level of oversubscription is okay when you go to using a SAS expander. A more common scenario is the use of an external JBOD storage enclosure. Those usually have 1 or 2 x 4-lane SAS connectors linking them to the main server. Let's assume 4 x 6Gbps, so ...


1

Yes, you need SAS expanders to get all the drives on there. Look up Backblaze's storage pods : http://blog.backblaze.com/2009/09/01/petabytes-on-a-budget-how-to-build-cheap-cloud-storage/ That card says it's a 4-lane port, so that's somewhat of a bottleneck. They make cards with more ports.


1

Self answer by David: So thanks for the comments, I will stop there trying to set up my RAID 1 on this machine. For any further question to this topic, this excerpt from the Dell hardware specification of this machine will be my answer :-) C1 MOTHERBOARD SATA CABLED, NO RAID, 1 H


1

no, he's talking about a 'built-in' firmware raid from the motherboard. NO, sorry that is not possible. You might be able to do software raid AFTER you load the o/s, using OMSA.


1

First check whether there are acutally drivers for your card in linux at all. It should have discovered your disks regardless of the RAID. In Linux it is usually not a big problem to install on a temporary disk, you can move the insallation relativly easy when using LVM. You could use a cheap stick first, and fiddle with the RAID later on. Out-of-tree ...


1

You may be able to get all of this information from within vCenter using the Hardware Status Page. The screenshot is of a Dell server, but these may show up for HP server - YMMV.


1

I think Option 1. is your best. Take 12x new HDDs, 1x new RAID controller Try to mirror (dd if= of=) old disks to the new ones 1:1 using any linux box. Build a new server using the 1x new RAID controller plus the 12x new HDDs Try to rebuild the array in the new server. Success? Great. Stop. Rebuild failed? Mirror the old disks to new ones again, try ...



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