Guest rosgiof@hotmail.it Posted July 21, 2008 Posted July 21, 2008 Hi all. I've googled a lot, but I've found out various and different opinions: Is it correct to use chkdsk /F and chkdsk /F /R on a RAID 1 system and on a RAID 5 (with 3 HDs) system ? All my systems are hardware RAIDs and the servers are domain controller with w2k srv and w2k3 srv. Thanks a lot. Bye, Rosgiof.
Guest Brian Cryer Posted July 22, 2008 Posted July 22, 2008 Re: Raid 1 and 5 Chkdsk <rosgiof@hotmail.it> wrote in message news:c25a8ff9-7d7c-4e2c-bbcd-743afbddfe19@z72g2000hsb.googlegroups.com... > Hi all. > > I've googled a lot, but I've found out various and different opinions: > > Is it correct to use chkdsk /F and chkdsk /F /R on a RAID 1 system and > on a RAID 5 (with 3 HDs) system ? > All my systems are hardware RAIDs and the servers are domain > controller with w2k srv and w2k3 srv. I would have thought so, yes - because a RAID controller should present the RAID as a single disk to windows and windows shouldn't even need to be aware that its a RAID. chkdsk /f checks for logical corruptions, which could still occur whatever type of RAID you have if you ever shutdown in an ungraceful manner. chkdsk /r checks for bad sectors. This is probably pointless because even if one of the physical disks had a bad sector the raid controller (whether raid 1 or raid 5) should return the correct contents. So I would have thought chkdsk /f but not /r. Presumably if the RAID is failing (controller error or multiple disk errors) then chkdsk might report an error but chkdsk will not be able to fix the problem because the problem is with the underlying RAID. In this scenario chkdsk might even make things worse! So if you ever need to run chkdsk also check the state of the RAID controller. -- Brian Cryer http://www.cryer.co.uk/brian
Guest Bryan Hughes Posted July 23, 2008 Posted July 23, 2008 Re: Raid 1 and 5 Chkdsk Read this http://www.dataclinic.co.uk/raid-server-faults.htm You should never run chkdsk in /F or /F/R mode on a RAID array. Chkdsk is not RAID aware, and will simply try to analyse and fix the NTFS tree as if dealing with a normal disk. In doing so, it can write over information in a degraded RAID array, that might have been recoverable at a lower level. You can run it in read mode, but I would use the RAID controllers software. You should be able access during machine boot up process. This should have several options on checking for disk failure and recovery. Chkdsk might be able to fix file system errors but it cannot do a surface scan since it does not have access to any of the physical surfaces. I have lost an array doing chkdsk on a raid array. That is why proper power backup, data backup and recovery procedures are such a critical part of any server setup. Bryan "Brian Cryer" <not.here@localhost> wrote in message news:u7kpnZB7IHA.4468@TK2MSFTNGP02.phx.gbl... > <rosgiof@hotmail.it> wrote in message > news:c25a8ff9-7d7c-4e2c-bbcd-743afbddfe19@z72g2000hsb.googlegroups.com... >> Hi all. >> >> I've googled a lot, but I've found out various and different opinions: >> >> Is it correct to use chkdsk /F and chkdsk /F /R on a RAID 1 system and >> on a RAID 5 (with 3 HDs) system ? >> All my systems are hardware RAIDs and the servers are domain >> controller with w2k srv and w2k3 srv. > > I would have thought so, yes - because a RAID controller should present > the RAID as a single disk to windows and windows shouldn't even need to be > aware that its a RAID. > > chkdsk /f checks for logical corruptions, which could still occur whatever > type of RAID you have if you ever shutdown in an ungraceful manner. > > chkdsk /r checks for bad sectors. This is probably pointless because even > if one of the physical disks had a bad sector the raid controller (whether > raid 1 or raid 5) should return the correct contents. > > So I would have thought chkdsk /f but not /r. > > Presumably if the RAID is failing (controller error or multiple disk > errors) then chkdsk might report an error but chkdsk will not be able to > fix the problem because the problem is with the underlying RAID. In this > scenario chkdsk might even make things worse! So if you ever need to run > chkdsk also check the state of the RAID controller. > -- > Brian Cryer > http://www.cryer.co.uk/brian > > >
Guest rosgiof@hotmail.it Posted July 25, 2008 Posted July 25, 2008 Re: Raid 1 and 5 Chkdsk Hi and thanks to all for your very kind help. Sorry for the delay of my answer but I was ill and didn't reach my PC. :-) So, if I don't use chkdsk on a RAID array, what tools could I run to test the disks? Only the RAID controllers utility that I access during boot? Are there any software that run under windows that could test the RAID disks? Thanks againg for the help. Bye, Rosgiof.
Guest Brian Cryer Posted July 25, 2008 Posted July 25, 2008 Re: Raid 1 and 5 Chkdsk "Bryan Hughes" <bhughes@notreal.org> wrote in message news:%23$4IVUO7IHA.1420@TK2MSFTNGP06.phx.gbl... > Read this http://www.dataclinic.co.uk/raid-server-faults.htm > > You should never run chkdsk in /F or /F/R mode on a RAID array. Chkdsk is > not RAID aware, and will simply try to analyse and fix the NTFS tree as if > dealing with a normal disk. In doing so, it can write over information in > a degraded RAID array, that might have been recoverable at a lower level. > You can run it in read mode, but I would use the RAID controllers > software. You should be able access during machine boot up process. This > should have several options on checking for disk failure and recovery. The key phrase there is "in a degraded RAID array". To which I quite agree. If there are problems with the RAID array then chkdsk won't fix them and it will probably only make things worse. However, where the RAID array is operating without problems then chkdsk can find and fix logical (i.e. file system) problems with out problem. I thought I'd made this clear in my post, but looking back I should have been clearer. > Chkdsk might be able to fix file system errors but it cannot do a surface > scan since it does not have access to any of the physical surfaces. I > have lost an array doing chkdsk on a raid array. That is why proper power > backup, data backup and recovery procedures are such a critical part of > any server setup. I accept that should have been clearer with terms in my original reply. When I referred to local problems I meant problems with the file system. Chkdsk is fine for these. Bottom line is that if you are using a RAID you ought to have something that warns you when there is a problem with the RAID. This is especially important since a RAID should allow you to continue working with a failed disk. -- Brian Cryer http://www.cryer.co.uk/brian > Bryan > > > "Brian Cryer" <not.here@localhost> wrote in message > news:u7kpnZB7IHA.4468@TK2MSFTNGP02.phx.gbl... >> <rosgiof@hotmail.it> wrote in message >> news:c25a8ff9-7d7c-4e2c-bbcd-743afbddfe19@z72g2000hsb.googlegroups.com... >>> Hi all. >>> >>> I've googled a lot, but I've found out various and different opinions: >>> >>> Is it correct to use chkdsk /F and chkdsk /F /R on a RAID 1 system and >>> on a RAID 5 (with 3 HDs) system ? >>> All my systems are hardware RAIDs and the servers are domain >>> controller with w2k srv and w2k3 srv. >> >> I would have thought so, yes - because a RAID controller should present >> the RAID as a single disk to windows and windows shouldn't even need to >> be aware that its a RAID. >> >> chkdsk /f checks for logical corruptions, which could still occur >> whatever type of RAID you have if you ever shutdown in an ungraceful >> manner. >> >> chkdsk /r checks for bad sectors. This is probably pointless because even >> if one of the physical disks had a bad sector the raid controller >> (whether raid 1 or raid 5) should return the correct contents. >> >> So I would have thought chkdsk /f but not /r. >> >> Presumably if the RAID is failing (controller error or multiple disk >> errors) then chkdsk might report an error but chkdsk will not be able to >> fix the problem because the problem is with the underlying RAID. In this >> scenario chkdsk might even make things worse! So if you ever need to run >> chkdsk also check the state of the RAID controller. >> -- >> Brian Cryer >> http://www.cryer.co.uk/brian
Guest rosgiof@hotmail.it Posted August 1, 2008 Posted August 1, 2008 Re: Raid 1 and 5 Chkdsk Ok, Brian, thanks very much for your help. Have you some suggestions to use a tool with RAID system? Thanks and bye bye. Rosgiof.
Guest Pauli Posted September 26, 2008 Posted September 26, 2008 Re: Raid 1 and 5 Chkdsk I have an MSI K9N SLI mb with a NVIDIA® nForce 570 SLI MCP Chipset. I have 3 disks installed, configured as Raid 5. (with 2 partitions) The F10 Bios showed the raid as Healthy, however, I have just installed Vista Ultimate 64 and the F10 Bios is now showing the raid as damaged. Two disks are OK and one is in error - even though there is no hw problem. At the start of the Windows install, I loaded the latest version of the floppy raid and SATA drivers (even though the "raw" windows installation could still see the partitions"). I have had a similar problem before when I scheduled a chkdsk /f /r in Windows Visa 64, after the reboot, the raid was shown as damaged. In this case I was able to rebuild the raid with MediaShield. To me it looks like during installation or during a chkdsk, Windows is not using the proper Raid driver and hence not maintiaining the Raid structure properly. The only way I was able to "recover" the situation was to use the disk management utility under windows to delete the "damaged" raid disk, the re-add it and rebuild the raid. The system is back "working OK". 1) How are you supposed to install windows on a Raid 5 cluster and why, after loading the driver at install time, did windows not maintain the raid 5 structure? 2) What can you do to keep the NTFS structure correct if every time you run CHKDSK it corrupts the raid 5 array?
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