Hi Ang, I don't think you've understood my questions on the NAS. I know what a NAS is, but you can get them as different OSs, such as Windows as the OS running Windows Storage Server 2003 or 2008, meaning that you still join it to your domain and log in and manage it just like a normal Windows server. Anyway.we digress. I assume from your answer you're using something like a NetApp Filer. Whilst it may be underutilised and your NAS admin says there's nothing wrong with it, everything will look normal if you're not looking in the right place. Read something like this: http://netappsky.com/storage-management/cifs-performance-is-slow-after-inves tigating-performance-issues-cifs-considerations/ There is definitely a problem\bottleneck with SMB, which is killing the box. The thing is, you can change those parameters on the Citrix servers and get more aggressive, but unless the NAS is setup correctly, it may be to no avail. Refer to this KB article for tuning the Citrix servers: http://support.microsoft.com/kb/324446 Cheers, Jeremy. From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of Angela Smith Sent: Friday, 1 July 2011 1:39 PM To: thin@xxxxxxxxxxxxx Subject: [THIN] Re: Session hangs/resets Hi Jeremy Thanks for the detailed email.. We are using Windows 2003 Enterprise (32bit). Servers have 10GB RAM, Dual Quad core CPU's File Storage is on a NAS Appliance (Network Attached Storage) so its an appliance (not Windows based). Citrix Server MaxMpxCt is set to 1024 MaxWork Items is set to 4096 NAS CIFS MPX is set to 1124 Perfmon results Redirector\Current Commands: Min 155, Max 246. Average 170 Server\Work Item Shortages: 0 Server Work Queues\Available Work Items: Min 30, Max 30, Average 30 As you can see from above The Redirector Current Commands are quite high. Our NAS Admin says there is no issue on the NAS side. What can I do to fix this on the Citrix Servers? Thanks Ang _____ From: jeremy@xxxxxxxxxxxxxxxxxxxx To: thin@xxxxxxxxxxxxx Subject: [THIN] Re: Session hangs/resets Date: Thu, 30 Jun 2011 18:45:09 +0800 Hi Ang, Ronnie has a good point. I know all about Notes 8.5 as I used to work for IBM J Notes 8.5 also uses heaps of memory. Are you using 2003 Enterprise or Standard? 32-bit or 64-bit? As for the SMB tuning, what is the NAS? Is it still a Windows 2003 or 2008 server? On the Citrix server you can use PerfMon to monitor the following: Redirector\Current Commands: Current Commands counts the number of requests to the Redirector that are currently queued for service. If this number is much larger than the number of network adapter cards installed in the computer, then the network(s) and/or the server(s) being accessed are seriously bottlenecked. The number indicated by the Current Commands counter indicates the number of pending commands that are waiting to be serviced by the local computer. This is the number of pending commands from the local computer to all destination servers. This means that if one of the destination servers does not respond in a timely manner, the number of current commands on the local computer may increase. The goal of a Terminal/Citrix Server deployment is to keep the Current Commands value to about 60 on heavily utilised servers. A Current Commands value of 80 means that on average you've got 80 pending SMB/RPC network I/O commands in the queue. With standard out-of-the-box tuning, it means that you're probably getting pretty close to the edge at times. When the pending requests queue is full, things stop (pause) momentarily until the queue has free slots. If settings such as the MaxMpxCt and MaxWorkItems values are not increased on the file server(s), anything at all that slows down your file server will potentially impact on your Terminal/Citrix Servers. Tuning MaxCmds on the Terminal/Citrix Server end won't provide any enhancement unless the file server end is increased as well. On the file server, assuming it's a Windows server, you can use PerfMon to monitor the following: Server\Work Item Shortages: It represents the number of times no work items were available or couldn't be allocated to service a file request. It indicates whether or not the InitWorkItems or MaxWorkItems parameters need to be adjusted. If you see any other value than zero, you need to start worrying. Upping the InitWorkItems or MaxWorkItems could help out here. Server Work Queues\Available Work Items: Shows the instantaneous number of available work items per CPU. A work item is typically a request from a client to the server; the server maintains a pool of available work items per CPU to speed processing. Sustained values smaller than ten means that the File server is running out of work items. When it does, performance really starts to plummet. If it reaches zero, clients may be unable to access files. Make sure this doesn't happen by upping the MinFreeworkItems value. There are a lot more things you can monitor on the Citrix servers, but this is a start. If you are experiencing an SMB bottleneck, I would expect to see a high number of Current Commands. Hope that helps. Cheers, Jeremy. From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of Hamilton, Ronnie Sent: Thursday, 30 June 2011 4:19 PM To: thin@xxxxxxxxxxxxx Subject: [THIN] Re: Session hangs/resets Hi Angela, I remember looking at issues relating to many open files and needed to do some SMD tuning at the time <http://blogs.citrix.com/2010/10/21/smb-tuning-for-xenapp-and-file-servers-o n-windows-server-2008/> http://blogs.citrix.com/2010/10/21/smb-tuning-for-xenapp-and-file-servers-on -windows-server-2008/ This blog might give you an idea, It's for 2008. I was using server 2003 at the time but don't have exact MS article at hand Ronnie From: thin-bounce@xxxxxxxxxxxxx [mailto:thin-bounce@xxxxxxxxxxxxx] On Behalf Of Angela Smith Sent: 30 June 2011 08:45 To: thin@xxxxxxxxxxxxx Subject: [THIN] Session hangs/resets Hi Im having an issue on my Windows 2003 Xenapp 5 Farm where Sessions keep locking up and just disconnecting, event logs say Event ID 50, and 26 for delayed write failed. This is particularly noticable with Lotus Notes 8.5 client which relies heavily on File Server. I've been doing research on this all last week with no luck at all. File server hosting user home drives/profiles is on the NAS. NAS is underutilised and Citrix Servers are all connected to Gig network again which is underutilised. No other applications get errors except for Lotus Notes, and when it crashes all of their applications crash. It just crashes the user's entire connection. There is no latency that I can see Has anyone seen this issue before? Ive had to reset over 300 connections in 1 month because of this issue. We have Session reliability enabled. Thanks Ang Visit our website : <http://www.ltai.ie> www.ltai.ie __________________________________________ Lufthansa Technik Airmotive Ireland Limited. Registered in Ireland. Reg. No. 45999. Registered Office: Naas Road, Rathcoole, Co.Dublin. Lufthansa Technik Airmotive Ireland Leasing Limited. Registered in Ireland. Reg. No. 140891. Registered Office: Naas Road, Rathcoole, Co.Dublin. __________________________________________ The information in this email and in any attachments is confidential and may be privileged. If you are not the intended recipient, please destroy this message, delete any copies held on your systems and notify the sender by return email. You should not read, retain, copy, disseminate, distribute, disclose or use this email or its contents in any way. Any such action is strictly prohibited. Thank you.