I saw a similar post here but I haven't tackled this yet and want to know if I face any hurdles before diving in. I have a PowerEdge 2800 with a PERC 4e/Di in a RAID 5 with three 320 SCSI drives at 68.24 GB each. I am adding in two new 73 GB drives and need to reconfigure the RAID. I bought the new drives direct from Dell. Is it easier to do this through the BIOS or through the Dell OpenManage Server Administrator? Does it matter that the two new drives are slightly bigger? About how long does the process take with 140 GB of total data?
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RAID 5 Rebuild Question 1
- Thread starter ScottWIT
- Start date
-
1
- #2
The new drives are OK if they are larger.
You will need to add these disks to the raid 5 array, in bios or open manage. Now the fun part, the drives added to the array do not add the new space to the raid volume. You will need to use a util to incorporate the new space from the added drives in the present raid 5 volume via....
Diskpart.exe
Dell has Expart.exe
I use Disk director from Acronis..
Dell Open manage will be easier for you.
How long, depends on the disk setup, file sizes etc. Count on a few hours, including the volume expansion. Run chkdsk before doing anything, correct errors if found with chkdsk /f. I would verify the drive array (consistency check) also.
Backup first
........................................
Chernobyl disaster..a must see pictorial
You will need to add these disks to the raid 5 array, in bios or open manage. Now the fun part, the drives added to the array do not add the new space to the raid volume. You will need to use a util to incorporate the new space from the added drives in the present raid 5 volume via....
Diskpart.exe
Dell has Expart.exe
I use Disk director from Acronis..
Dell Open manage will be easier for you.
How long, depends on the disk setup, file sizes etc. Count on a few hours, including the volume expansion. Run chkdsk before doing anything, correct errors if found with chkdsk /f. I would verify the drive array (consistency check) also.
Backup first
........................................
Chernobyl disaster..a must see pictorial
- Thread starter
- #3
Interesting.... I spoke with two people at Dell and they said nothing about using a util to gain some space. That is, afterall, my whole objective in doing this! Thanx for the info.
Another question... one guy at Dell said I would have restore all my files AND reinstall Windows Server 2003 after the RAID 5 reconfiguration was finished. He then corrected himself and said he was wrong but he nearly made me faint!! I will not have restore my files or reinstall Windows unless there's a total disaster like a loss of power, right?
Another question... one guy at Dell said I would have restore all my files AND reinstall Windows Server 2003 after the RAID 5 reconfiguration was finished. He then corrected himself and said he was wrong but he nearly made me faint!! I will not have restore my files or reinstall Windows unless there's a total disaster like a loss of power, right?
Dell tells everyone the same story.
" I will not have restore my files or reinstall Windows unless there's a total disaster like a loss of power, right?"
There always is some danger in manipulating partition space and I am always nervous doing it but I have done this numerous times with no issues, as have many others.
Yes, I would highly recommend this be done with a UPS attached
a post at Dell's site
Dell’s manual, search for expansion or reconstruct, this is just to add the new drives to the present array, you still need a util as per previous post to incorporate the new space.
........................................
Chernobyl disaster..a must see pictorial
" I will not have restore my files or reinstall Windows unless there's a total disaster like a loss of power, right?"
There always is some danger in manipulating partition space and I am always nervous doing it but I have done this numerous times with no issues, as have many others.
Yes, I would highly recommend this be done with a UPS attached
a post at Dell's site
Dell’s manual, search for expansion or reconstruct, this is just to add the new drives to the present array, you still need a util as per previous post to incorporate the new space.
........................................
Chernobyl disaster..a must see pictorial
- Thread starter
- #5
Great, thanks a lot for the info. This actually doesn't look as bad as I thought. Sounds like the reconfiguration through Dell Open Manage will take a few hours and then it's probably best to run diskpart in safe mode after that, right?
In addition to having a UPS for this in case of a power outtage should I disconnect the server from the network? I will instruct all users to not use it during this time but I was thinking of unplugging the cable just to be sure.
In addition to having a UPS for this in case of a power outtage should I disconnect the server from the network? I will instruct all users to not use it during this time but I was thinking of unplugging the cable just to be sure.
Safe mode, never tried it but logical as it removes overhead from drivers etc.
I would at least insure there is no disk access from users, I would take it off network.
Remember check the disks for errors before proceeding
........................................
Chernobyl disaster..a must see pictorial
I would at least insure there is no disk access from users, I would take it off network.
Remember check the disks for errors before proceeding
........................................
Chernobyl disaster..a must see pictorial
- Thread starter
- #7
Defragging the drives should speed up the process somewhat (4-7%), but most of the time involved as you say is restripping, and the adapter verifying the media as it is writing.
While you at it, run disk clean-up, delete all files in all tmp directories (profiles/windows temp folder), use search to find all tmp files and delete, then defrag.
One thing you should institute is a scheduled consistency check, weekly or bi-monthly if possible, I also schedule patrol reads to turn on and off, in off hours, every weekend, if off hours permit.
Example of CC command line to place in a scheduled task to check the C: drive
"C:\Program Files\Dell\SysMgt\ArrayManager\amcli.exe" /c1/e0/v
For a D: drive
"C:\Program
Files\Dell\SysMgt\Array Manager\amcli.exe" /c2/e0/v
I use lsilogic's downloaded util for stopping and starting patrol reads, I place the commands in separate .bat file and schedule the bat files to run off hours, every weekend
if possible
start patrol reads...
MegaPR -startPR -a0
Stop it....
MegaPR -stopPR -a0
Patrol reads takes about 2-3 hours to complete on an array of your size, Approx same with a CC. Consistency check primarily concerns itself with parity checking, patrol reads with media errors. Patrol reads are important as it checks all sectors of the disks in the array. Normally an adapter will mark a sector going bad when it reads from a sector with data, it will not check UNUSED sectors, so the danger with arrays is multiple errors can exist in unused sectors, enough that when an array degrades or is migrated the multiple errors show up, too many for the adapter to manage ..end result more than one drive fails at the same time, a complete array failure.
The larger the array size, the more regular runs of the both above are needed. Read the following Intel link, in the section "why raid 6". I not advocating raid 6 here, it just explains the need to run CC checks/patrol reads on larger raid 5 arrays.
Good Luck
........................................
Chernobyl disaster..a must see pictorial
While you at it, run disk clean-up, delete all files in all tmp directories (profiles/windows temp folder), use search to find all tmp files and delete, then defrag.
One thing you should institute is a scheduled consistency check, weekly or bi-monthly if possible, I also schedule patrol reads to turn on and off, in off hours, every weekend, if off hours permit.
Example of CC command line to place in a scheduled task to check the C: drive
"C:\Program Files\Dell\SysMgt\ArrayManager\amcli.exe" /c1/e0/v
For a D: drive
"C:\Program
Files\Dell\SysMgt\Array Manager\amcli.exe" /c2/e0/v
I use lsilogic's downloaded util for stopping and starting patrol reads, I place the commands in separate .bat file and schedule the bat files to run off hours, every weekend
if possible
start patrol reads...
MegaPR -startPR -a0
Stop it....
MegaPR -stopPR -a0
Patrol reads takes about 2-3 hours to complete on an array of your size, Approx same with a CC. Consistency check primarily concerns itself with parity checking, patrol reads with media errors. Patrol reads are important as it checks all sectors of the disks in the array. Normally an adapter will mark a sector going bad when it reads from a sector with data, it will not check UNUSED sectors, so the danger with arrays is multiple errors can exist in unused sectors, enough that when an array degrades or is migrated the multiple errors show up, too many for the adapter to manage ..end result more than one drive fails at the same time, a complete array failure.
The larger the array size, the more regular runs of the both above are needed. Read the following Intel link, in the section "why raid 6". I not advocating raid 6 here, it just explains the need to run CC checks/patrol reads on larger raid 5 arrays.
Good Luck
........................................
Chernobyl disaster..a must see pictorial
- Thread starter
- #9
Couple more questions... I read on Dell's site that it is not necessary to take the server offline during reconfiguration of the RAID array. So I called them up and they said the same thing, that leaving it online would not harm anything. Is this true?
Secondly, regarding using diskpart or extpart to extend my data partition afterwards I have read that they will NOT work on a dynamic disk. When I called Dell they said diskpart would work on dynamic disks but they didn't seem real confident about that. So has anyone had experience with that?
Secondly, regarding using diskpart or extpart to extend my data partition afterwards I have read that they will NOT work on a dynamic disk. When I called Dell they said diskpart would work on dynamic disks but they didn't seem real confident about that. So has anyone had experience with that?
Mostly every raid procedure works with the server up and running, but I try to do most procedures offline (from a server start, without the OS or disk access involved)...IF it is practical..less interference, safer.
To be honest, I never tried the mentioned utils on Dynamic disks, as only a couple of my clients have small enough networks, where a simple raid 1 using dynamic disks is practical... have not worked on raid 5 where the disks are Dynamic disks in may years . I have an extreme aversion to dynamic disks. With hardware raid, the array sets should NEVER be converted to dynamic, this just compounds the complexity of disk issues with no benefits. Nothing like OS corruption corrupting the dynamic disk structure, and having to perform a resurrection on a production server.
I have tried Ghost, and Acronis with dynamic disks and neither one enjoys working with them, but Ghost does work.
If neither free util works on the dynamic disks, and your desperate, clone the raid 5 to an IDE/SATA drive with Ghost, as it will clone it, but refuses to create a dynamic disk out of the IDE or SATA, which is good... than reverse clone from the IDE or SATA back to the raid 5. Acronis refused to clone a dynamic disk for me a while back, so that option seems to be out.
........................................
Chernobyl disaster..a must see pictorial
To be honest, I never tried the mentioned utils on Dynamic disks, as only a couple of my clients have small enough networks, where a simple raid 1 using dynamic disks is practical... have not worked on raid 5 where the disks are Dynamic disks in may years . I have an extreme aversion to dynamic disks. With hardware raid, the array sets should NEVER be converted to dynamic, this just compounds the complexity of disk issues with no benefits. Nothing like OS corruption corrupting the dynamic disk structure, and having to perform a resurrection on a production server.
I have tried Ghost, and Acronis with dynamic disks and neither one enjoys working with them, but Ghost does work.
If neither free util works on the dynamic disks, and your desperate, clone the raid 5 to an IDE/SATA drive with Ghost, as it will clone it, but refuses to create a dynamic disk out of the IDE or SATA, which is good... than reverse clone from the IDE or SATA back to the raid 5. Acronis refused to clone a dynamic disk for me a while back, so that option seems to be out.
........................................
Chernobyl disaster..a must see pictorial
- Thread starter
- #11
very interesting. well, the previous admin here set the disks up as dynamic. not sure why but it's my problem now. i suppose i could just create a brand new partition after the array reconfiguration is done but ideally i would prefer to just extend the present data partition so i don't have to mess around with explaining this to my users. i might call microsoft and see what they say because on their site they clearly state that dispart can be used with dynamic disks.
On the Dell server (raid) forum someone did a small write up, stating neither of the utils work on Dynamic disks. As to MS, unless you get a tech in the upper echelons, you will not get a definitive answer.
There are ways to convert Dynamic to basic disks via registry entries, but I tried it once, it worked, until the next SP patch came along.
Good Luck
........................................
Chernobyl disaster..a must see pictorial
There are ways to convert Dynamic to basic disks via registry entries, but I tried it once, it worked, until the next SP patch came along.
Good Luck
........................................
Chernobyl disaster..a must see pictorial
- Thread starter
- #13
Ok... even though Ghost says it's compatible with XP/Vista it does say in the system requirements that it works with dynamic disks so it should be fine with Windows Server 2003, right?
So essentially I can clone the data partition with Ghost to an external drive, delete the current data partition, recreate the partition to include the extra space I now have and then restore the data to it with Ghost, right?
Of course I will back the data up with our methods as well just in case.
So essentially I can clone the data partition with Ghost to an external drive, delete the current data partition, recreate the partition to include the extra space I now have and then restore the data to it with Ghost, right?
Of course I will back the data up with our methods as well just in case.
Your procedure is correct.... run chkdsk and a surface test on the source and destination drives before cloning. If possible, after cloning, view the clone's data, run chkdsk again, before doing the reverse clone.
I use Ghost very little, but it should work as you describe above on 2003. If the temporary disk is large enough, and the OS is on the raid 5, clone the entire raid, this way you can start the cloned disk up, making sure the temporary cloned disk works perfectly before reversing to the new array.
Read this, note the reference to having an over sized disk to use, if possible, as a temorary clone to cut down the cloning time
........................................
Chernobyl disaster..a must see pictorial
I use Ghost very little, but it should work as you describe above on 2003. If the temporary disk is large enough, and the OS is on the raid 5, clone the entire raid, this way you can start the cloned disk up, making sure the temporary cloned disk works perfectly before reversing to the new array.
Read this, note the reference to having an over sized disk to use, if possible, as a temorary clone to cut down the cloning time
........................................
Chernobyl disaster..a must see pictorial
Forgot, I suppose you already know you can minuplate the partition size to the "new" raid 5 with Ghost so you will not need the partition expanding utils.
........................................
Chernobyl disaster..a must see pictorial
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Chernobyl disaster..a must see pictorial
- Thread starter
- #16
Well, I decided this morning to just go for it and try diskpart to see if it would work... and it did. I was nervous because I read a post where a guy said it could possibly cause a loss of data if tried on a dynamic disk. But no harm done and it extended my data partition to use the new space I added just like I wanted. Thanks for all your help and info.
Great... nice to get that endorphin rush from a calculated risk.
Yes, I read a few posts where partition manipulation has destroyed arrays; only fools, incompetents or psychopath are not nervous doing this.
........................................
Chernobyl disaster..a must see pictorial
Yes, I read a few posts where partition manipulation has destroyed arrays; only fools, incompetents or psychopath are not nervous doing this.
........................................
Chernobyl disaster..a must see pictorial
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